Episode 26: Matters of Life & Death in Roman Astrology

February 9, 2023

As Rome expanded to the East, the cultural influence of the Greeks deepened, and this included a strong interest in astrology. Despite resistance from conservative Romans, by the Imperial Era, astrology played a critical role in Roman politics, both as a tool to support conspirators attempting to assassinate emperors, and wielded by emperors as a way to eliminate challenges to their power.


Good evening, and welcome to the Song of Urania, a podcast about the history of astronomy from antiquity to the present with new episodes every full moon, or thereabouts. My name is Joe Antognini.

We took a bit of a detour in the last episode to look at an astronomical event or astrological sign that appeared in the obscure corner of Judea in the Roman Empire around the turn of the millennium. But in this episode we’ll return to the center of the action in our look at Roman astronomy. Or really, I should say Roman astrology, because the Romans cared little for what we would call astronomy today.

The Romans, as has often been said, were an intensely practical people. Unlike those Greeks, who would fritter away their days debating the finer points of philosophy, the Romans had no interest in knowledge for its own sake. They wanted something they could use. Modeling the motions of the planets through the heavens was only so much nonsense to them. But if you could use that to tell you something interesting, say, when the next emperor would die, or more prosaically whether or not a boxer you wanted to bet on would win an upcoming fight, well that was an entirely different story. The Romans were extremely interested in that.

That intense interest meant that astrology was a potent political tool, in a way that is maybe hard for those of us in the modern world to grasp. Consequently, astrology was highly regulated in ancient Rome and astrologers often acted as a power behind the throne or were key in aiding conspiracies.

But before diving straight into the influences of astrology on Roman politics, it’s worth backing up a little bit to understand how Rome got to that point in the first place, because astrology did not always play such a, forgive the pun, starring role in Roman culture. The Romans, of course, had always been superstitious, but in Rome’s early days the superstitions were largely homegrown and consisted of divination by looking for omens in the natural world, say, the flight of birds, or the entrails of sacrificed animals.

The origins of Roman astrology lay far to the East, ultimately with the Babylonians. In the first few episodes of this podcast we saw how the Babylonians interpreted the motions of the planets through the skies to portend victories or calamities for kings and nations. And this astrology was old. Very old. It far predated the civilization of the Romans. So, by the time the Hellenistic Era rolled around in the late 300s BC, the Babylonian astrologers had acquired a reputation in Greece for their ancient and mysterious skills. Indeed, when Alexander the Great was marching on Babylon, the astrologers of the city met him outside and warned him against entering the city walls. The astrologers told him that they had seen an omen in the stars that a king would die in Babylon. It was really for his own safety, you see, that he should stay away. But that was not all, they had also discovered that Alexander could avert this danger if he rebuilt a tomb to one of their gods and entered the city along a particular route. Now, the ancient accounts suggest that Alexander probably thought that this was all hokum and just a ruse to keep him out of their city for a little while longer. But nevertheless he had heard enough of their skills that he thought it was probably better to be on the safe side and he did acquiesce to the astrologers’ requests.

The reputation of the Babylonian astrologers seems to have been further burnished by a few incidents in the wars of the Diodochi after Alexander’s death. In the aftermath, one of Alexander’s officers, Seleucus ended up as the governor of Babylonia under the general Antigonus Monophthalmus, whom you might remember from Episode 21 because name meant one-eyed because, well, he had one eye. One of Antigonus’s officers committed some offense or other in Babylonia and Seleucus punished the officer without obtaining permission from Antigonus. Antigonus then demanded tribute from Babylonia which Seleucus refused to pay. Seeing which way the winds were blowing, Seleucus decided to flee to Egypt, far from any reprisals from Antigonus. When Antigonus arrived at Babylon to deal with Seleucus, he learned that Seleucus had fled. And what’s more, the city’s astrologers then warned him that if Seleucus escaped his grasp, all of Asia would fall to Seleucus’s rule and Seleucus would kill Antigonus to boot. Now Antigonus generally did not take diviners seriously, but in the end, Seleucus did manage to flee to Egypt and in due time killed Antigonus in battle and founded the Seleucid Empire which ruled much of the east for centuries.

There was another story involving Seleucus and the astrologers once again about a decade later. Seleucus then was founding a new city on the Tigris River, modestly named Seleucia. Learning from the lesson of Antigonus that it was wise to heed the astrologers, he consulted with them to find out the most propitious time to lay the cornerstone of the city. For unclear reasons, Seleucus’s relationship with the astrologers had soured by this point and the astrologers decided to deceive him. Instead of giving him the time that was most propitious to lay the cornerstone, they gave him a time that was not propitious at all. They then watched as the workers went about laying the foundations of the city. But to the amazement of everyone watching, and for perhaps the only time in history, the workers began working inexplicably quickly and could not be slowed even when the foremen tried to stop them. Against their orders, the cornerstone was laid at a different time, which happened to be precisely the most auspicious of all. The astrologers were then called before Seleucus to explain what he had just witnessed. They managed to obtain a promise of mercy and then told him of their deception and how the cornerstone had nevertheless been laid at the most auspicious time. Evidently the city was fated to be one of the greatest in history and the fate of the city could not be changed, even by wily astrologers.

Now, of course, it is unlikely that these two events did in fact occur in history, but the later historians who told these tales did so to impress on the reader the prodigious abilities of the Chaldean astrologers and that to ignore them was to do so at your own peril.

Now, up until the Hellenistic Era, it seems that the Greeks were aware of this tremendous reputation that the Chaldean astrologers enjoyed. But there was little interaction between Greeks to the west and the astrologers themselves. And this makes sense, the Chaldean astrologers were a valuable source of state power. They weren’t about to be allowed to just roam to the four corners of the earth and spill their secrets. But after Alexander’s conquests, these cultural contacts became far deeper and over the years a stream of Chaldean astrologers made their way west and shared the methods of Babylonian astrology with the Greeks. The first we have record of was Berossus, whom I mentioned all the way back in Episode 4, who moved to the Greek island of Cos probably in the early third century. About a generation later a Chaldean astrologer by the name of Sudines moved to Pergamum, which by that point was an important place of scholarship and had a tremendous library, rivaled only by that in Alexandria. He seems to have made some contributions to astronomy proper by producing some astronomical tables and measuring the length of the year. But some of his most novel contributions were in writing about the astrological properties of gemstones.

During the Hellenistic era, many of these Chaldean astrologers didn’t only travel to Greek areas but went to Egypt as well, and from there these ideas transferred from Egypt to Greece thanks to the close cultural connection of those two lands. Throughout our long tour of Greek astronomy every Tom, Dick, and Harry I told you about had at some point in their youth traveled to Egypt and learned the secrets of astronomy and geometry from the priests there. So, much of the influence of Babylonian astrology was mediated through the Egyptians. In fact, over the 20th century there was quite a lot of debate as to whether or not Egyptian or Babylonian astrology came first and which one influenced the other. These days the debate seems to be fairly settled on the precedence of Babylonian astrology. But the ties between the two were quite strong, and in turn, both of them strongly influenced Greek astrology.

Well, the Greeks had about one and a half centuries for the astrological ideas of the Babylonians to percolate in their culture. But during the 2nd century the Romans swept in and what had once been a collection of independent kingdoms and city-states became subsumed into the rapidly growing Roman Republic. So it’s about in the middle of the 2nd century BC that we start seeing Greek philosophers in turn traveling west and spreading their ideas in Rome. In particular, if we could point to one moment where the Romans began to be interested in Greek thought, it was the year 155 BC. Without getting too deep into the backstory, Athens, which was then under Roman rule, had attacked the town of Oropus and as punishment, Rome had levied a fine on Athens of 500 talents, a prodigious sum of money. In an attempt to wriggle out of the fine, Athens sent three philosophers to Rome as ambassadors to try to negotiate the fine lower. These were Carneades of Cyrene, Diogenes the Babylonian, and Critolaus. Their reputations seem to have preceded them and they were met with good humor by the Romans. There is a story that Aulus Albinus, a Roman praetor at the time, was speaking with Carneades and Diogenes, Carneades being a member of the Skeptical School and Diogenes being a Stoic. Albinus said to Carneades, “In your view, Carneades, I am not a real praetor, nor is this a real city.” Carneades responded, “In the opinion of our Stoic friend here, you are not real.” With time to kill in Rome, the three philosophers began doing what they did best — teaching philosophy. Carneades, in particular, seems to have had an oratorical flair and one day went out into the streets and expounded a passionate and eloquent lecture on the value of Roman justice. But the next day, now having attracted an even larger crowd, he expounded an equally passionate and eloquent lecture which rebutted each of the arguments he had made the previous day. Then to his stunned audience he made the argument that justice itself was not a well defined concept.

Well, out in the crowd was a senator named Cato the Elder, and he recognized how subversive these arguments were. Cato persuaded the Senate to expel Carneades back to Athens where he couldn’t corrupt the minds of the Roman youth. But Carneades was just one of many Greek philosophers who spread their ideas in Rome at the time. A few years earlier, the philosopher Crates of Mallus also spent some time in Rome as an ambassador, though the sources conflict as to which city he was representing. Unfortunately for Crates during his stay in Rome he fell into an open sewer and broke his leg, so he ended up staying in Rome quite a while longer than he originally intended. But while he was laid up in bed, he made productive use of his time corrupting the minds of the Roman youth by teaching them philosophy.

Now, the Greek philosophers that came over to Rome in the middle of the second century were actually pretty skeptical about astrology on the whole. Carneades in particular had voiced the most strenuous arguments against the discipline that was starting to gain popularity in Rome at the time. Carneades levied five main arguments against astrology, though these arguments were by no means unique to him.

To start off, Carneades argued that even if there was some merit to astrology, it would be of no use to us, because in general no one could measure the positions of the planets in the sky precisely enough at the exact time of an individual’s birth. So as a practical matter astrology as a tool for determining the fate of an individual was dead on arrival. But Carneades went further and added a few more arguments against the validity of astrology. His next argument was that anyone can see that people are influenced by their environment. People born in Athens exhibit one set of customs, and people born in Egypt exhibit another, even though the people in Athens were born at all different times. Furthermore, if the stars were truly influencing events here on Earth, why would their effects be limited to humans? After all, the Sun’s influence is borne by everything on Earth. It affects planets and animals just as much as humans. So should it not be the case that an astrological omen in the heavens should apply equally well to an animal as to a man? If the stars display the sign of the birth of a great leader, would that mean that a dog born that day is destined to be the leader of all dogs? But probably the strongest argument against astrology levied not only by Carneades, but many skeptics of astrology of the time, was the argument of twins. Twins are born under exactly the same stars. Yet they very frequently have radically different lives. One lives long, the other dies young. One acquires great wealth, the other falls into poverty. If the stars are responsible for setting their destinies, how can you explain even a single case where one twin meets a different destiny than their counterpart?

Another argument against the merits of astrology of the time, not due to Carneades specifically, was that the premise of the associations didn’t make any sense to begin with. For example, someone born under the sign of Leo, the Lion, is assumed to have the qualities of a lion — strength and courage. But you wouldn’t expect that someone literally born next to a real, physical lion would have those qualities. So why should being born under its astrological sign bear those qualities?

In the end though, these kinds of philosophical arguments were no match for the waves of astrologers who made their way west to Rome during the 2nd century BC. During this century, Romans of the upper classes became more and more taken by Greek culture, and that included an interest in astrology. Now, as in any society, these kinds of social trends never include everybody. Cato the Elder was famously opposed to the influence of Greek culture in Rome. Cato was of the opinion that astrology was a permissible if perhaps distasteful belief for plebeians or slaves, but was certainly not acceptable for patricians. And more generally, Cato was of the old Roman school of thought that an excessive interest in philosophy was not appropriate for the Roman aristocrat who should be concerned with practical matters of politics and war. But ultimately Cato ended up being yet another man standing athwart history yelling stop.

Now, I’ve already mentioned the influence of the groups of Greek philosophers who traveled to Rome on official duties. But probably even more important for the general percolation of Greek culture in Rome was a less voluntary migration. As Rome conquered Greek lands, a stream of slaves made their way west. Educated Greek slaves would frequently end up in the employ of aristocratic Romans to tutor their children. As the older generations gave way to the next generations who had been raised on Greek scholarship, it is no surprise that by the end of the 2nd century, Roman culture began to look more Greek. One of the symbolic turning points, at least that later authors claimed, was due to the influence of the great Roman general Scipio Africanus. Scipio was a huge enthusiast of Greek culture and in an attempt to emulate Alexander the Great, he took the radical step of shaving his beard. After Scipio defeated Carthage in the Second Punic War, his popularity in Rome was such that everyone in town wanted to look like him and the clean shaven look became de rigueur among aristocratic Romans. Which, in the end is a bit ironic since the Greeks themselves did not shave their beards and regarded doing so as being rather effeminate. Now I should mention that this explanation of the Roman fashion for shaving is disputed by modern historians. Some argue that the clean shaven look had been popular in Rome long before Scipio Africanus. But it is nevertheless indicative of the influence of Greek culture that Roman authors pointed to the influence of the Greeks as being the cause for the rather unusual practice in the ancient world of regular shaving that Roman men engaged in.

Now of course, Greek culture was multifaceted, and as we’ve seen over the many episodes on Greek astronomy, there was a wide variety of philosophical schools. We met Carneades who was a Skeptic, which was one of the newer schools, but many of the older ones were still kicking around, the Peripatetic School of Aristotle, the Platonists, the Pythagoreans, the Epicureans. But the one school that found the most popularity in Rome was Stoicism. Now to try to keep myself on track and not drift too far away from Roman astrology, I won’t go too deep into the history and tenets of Stoicism. But unlike most of the other Greek philosophical schools, which tended to obsess over the finer points of epistemology or ontology, Stoicism was more oriented towards shaping the mind so as to be best equipped to handle the vicissitudes of life. Central to Stoicism was the idea that although you could not control external events in the world, you could control your interior mind — you could control how those external events affected you. And with proper control of oneself, you could always live a good life no matter what life threw at you. For the practical-minded Romans, this was a philosophy they could get behind.

The popularity of Stoicism in Rome seems to have complemented the rise in the popularity of astrology over the second century. Of all the Greek philosophical schools, Stoicism was the most amenable to astrology. Most of the others were highly skeptical in their temperament — and here I’m using the word skeptical in the modern sense, not referring to the literal Skeptical School. They were often interested in demonstrating what we did not know as much as what we did. But the Stoics were less keen in playing games like that. Now, it’s certainly the case that several of the prominent Stoic philosophers that we’ve already met, like Diogenes the Babylonian and Crates of Mallus, were skeptical of astrology. But go back to the founder of the Stoic school, Zeno of Citium — not to be confused with the Zeno of Zeno’s Paradoxes that we met back in Episode 12. This later Zeno was sympathetic to the ideas of astrology. And the basic premise of astrology is that one’s fate in life is ordained by the star’s. This meshes well with the Stoic outlook that one has little control of what the world throws at you. All you can control is how you react to it. The idea of Fate played an important role in the mindset of many Stoics. A famous motto of the Stoics was “Ducunt volentem fata, nolentem trahunt,” which means “Fate guides the willing, and drags along him who resists.” So while astrology was not always favored by the leaders of the Stoic school, among its rank and file adherents astrology just grew more and more popular over time.

By the late Roman Republic astrology pervaded culture. We saw in the last episode how coins in the Roman Empire frequently bore astrological symbols. Buildings bore astrological symbols as well. Astrological references showed up frequently in Roman literature and drama. A famous character of the writer Petronius named Trimalchio is a former slave who becomes a wealthy merchant and whose ostentatious behavior is meant to lampoon the nouveau riche in Rome. Among Trimalchio’s many excesses is a twelve-course feast in which every dish corresponds to a sign of the zodiac. Plautus’s play Rudens opens with a monologue by the star Arcturus.

Now an enthusiasm for astrology was not limited to the upper class. The plebeians also had a great deal of faith in astrology. In addition to the prominent philosophers who made their way west around the 2nd century, there were undoubtedly legions of obscure astrologers who travelled from town to town and tried to make a modest living reading the stars for the commoners. Some of the texts we have show just how specific astrology had become to help answer the average Roman’s most pressing questions. Of course we’re all familiar with the 12 signs of the zodiac, each one spanning 30 degrees across the ecliptic. But each sign was in turn divided into 3 sections that were 10 degrees across. And these, in turn, were divided even further. Each of these regions, called decani, were associated with particular questions, and the list of these questions is indicative of the kinds of things that the common people wanted to know. Should I get married this year? Will my baby be a boy or a girl? Is the woman I want to marry a virgin or not? Will I be rich or poor? Was the dream I had last night a good omen or a bad omen? Will I live a long time? Will a sick relative recover or die? Will I win my lawsuit at court? Roman satirists mocked these common astrologers who on the one hand claimed vast powers at divining the future from the heavens, and on the other hand charged the equivalent of a few bucks for their services.

Now it’s worth at this point drawing a distinction between two kinds of astrology: fatalistic astrology and catarchic astrology. Fatalistic astrology holds that the stars unalterably determine fate on Earth. Catarchic astrology is more wishy washy and simply holds that the stars influence events on Earth, but they do not inescapably determine them. In Rome, and generally throughout history, the ideas of fatalistic astrology have only really been popular among a small group of intellectuals. At root, it’s a fairly pessimistic kind of theory since it completely rules out the possibility of free will. As much as you might try to avoid your destiny, there is no escaping it. And many of the famous Greek tragedies like Oedipus play on these ideas, where in the very attempt to avoid one’s prophesied fate, one brings it about. More humorously, the writer Lukillios poked fun at fatalistic astrologers by writing about an astrologer named Aulus who predicted the time of his own death. When the day came and he hadn’t died, the astrologer grew very sad and hung himself. Of course, with that said, fatalistic astrology is in some ways right at home in modern science. At least as we understand the laws of physics today, all matter behaves deterministically, there is no room for free will. The fate of the universe is precisely determined by the laws of physics.

But these kinds of ideas have always only appealed to a limited number of people, either weirdos who like the idea of the impossibility of free will, or people who are at least resigned to the logic of it. But among most everyone else it’s an uncomfortable idea. One of the questions that Greek and Roman writers wrestled with was how you could possibly account for concepts like virtue and justice in a world ruled by fatalistic astrology. After all, if there is no free will and the stars determine everything you do, it seems as though someone who murders his own mother cannot be held responsible. The stars made him do it. And there’s no reason to praise a great soldier. He had no say in his glorious deeds, it was all predetermined by the stars. So the alternative of catarchic astrology which left some room for free will, was always far more popular. The idea was that the stars weren’t inescapably determining your fate, they were just thumbing the scales, so to speak. And that meant that if you knew how they worked — which side of the scale they were going to thumb and when, you just might be able to use that to your advantage. And everyone likes the idea of getting whatever advantage they can in life.

Now so far the astrology in Rome I have been telling you about seems pretty tame. People wondering about the gender of their baby, whether or not their spouse was having an affair, whom they should bet on in the chariot races, and so forth. Important to them, for sure, but not really of much interest to anyone else. So it’s easy to fall into the trap of thinking that that was all there was to the astrology of the day, because that’s more or less how astrology works today. Some people, actually quite a lot of people, use it today to understand their personal relationships, but that’s about the extent of it. But faith in astrology was far deeper in ancient Rome and that led to it being an incredibly potent political tool, to an extent that is hard to fathom today. But if you put yourself in the mindset of a true believer, if there is a revolt or a conspiracy of some sort and the astrologers say that its success is inevitable, written in the stars, or that it is doomed to fail, well, you’re going to want to be on the right side of history. Among the plebeians, astrology played a crucial role in one of the major slave rebellions, and a more minor role in another. In the first slave rebellion, called the First Servile War of 135–132 BC, the leader of the rebellion was a man in Sicily named Eunus, who claimed to have prophetic powers. Now, Eunus was a general kind of wonder worker rather than an astrologer specifically. It seems that he wove in astrological omens into his prophecies, but his main claim to leadership was that he was able to talk to the Gods. He awed crowds by breathing fire as he spoke. A Roman author named Florus explained this as being a magic trick where he took a nutshell, poked a number of holes in it, and placed a burning ember inside. The nutshell kept it from burning his mouth and when he blew out, sparks would come out of his mouth.

But astrology played a more prominent role in the Second Servile War which occurred about 30 years later from 104 to 100 BC, also in Sicily. This time, one of the leaders of the rebellion, a man named Athenion, was first and foremost an astrologer. Now Athenion was wise enough to know that it actually wasn’t the smartest idea to be the public face of the rebellion. So he was more than willing to let a more ambitious slave named Salvius Tryphon play that role. But Athenion played his part by convincing his fellow slaves to join in in the rebellion by telling them that the stars were absolutely unambiguous that the success of the rebellion was inevitable. All they had to do was rise from their chains and they would obtain freedom and glory. So in this event you can start to see the power of astrology in the ancient world. If you were a slave going up against the might of the Roman Army, you wanted a higher power on your side, and what higher power could there be than inexorable destiny traced out by the stars in the sky?

Astrology as a tool to control the unwashed masses also came up a few times in the Roman Army itself. In June 168 BC there was a lunar eclipse on the eve of a battle between the Romans and the Macedonians, the Battle of Pydna. Traditionally, when the Roman soldiers saw a lunar eclipse, they would be terrified and would bang their pots and pans and raise torches to the sky in an effort to bring back the light of the Moon. But in this case because the eclipse happened the night before a battle the commander, a general named Lucius Aemilius Paulus wanted to take no chances of the troops getting spooked by the event. So that evening, before the eclipse was to occur, he gathered his troops and explained to them what was going to happen. The Moon would go dark for several hours and that this was simply due to the fact that the Sun was on the opposite side of the Earth as the Moon and the Moon therefore fell into the shadow of the Earth. This was just something that happened from time to time and was nothing to fear. Meanwhile in the Macedonian camp, the equally superstitious troops got no such forewarning from their leaders. When they saw the Moon disappear that night they assumed that it portended the death of their king and became terrified, and ultimately lost the battle the next day. Nevertheless, although Aemilius Paulus clearly understood the mechanistic explanation of the lunar eclipse, he must have believed at some level that three was something more going on because after the light of the Moon returned, he sacrificed 11 cows in thanksgiving. After all, it couldn’t hurt, just in case the philosophers were wrong.

Again, Roman leaders were a pragmatic people. They weren’t interested in obtaining the truth and enlightening the masses to shape them into well rounded and self-actualized individuals, they were interested in getting things done. Astrology was a tool of social control. When it wasn’t in their interest that the troops know the cause of a lunar eclipse, the troops didn’t know. We see this about two centuries later, during the reign of Emperor Tiberius, when there was a mutiny in the legions in Pannonia. Tiberius sent his only son, Drusus to calm things down, which should give you an indication of how bad things had gotten out in the Roman camps. But one night as things started to get out of hand, there was a lunar eclipse. Now, Drusus could have followed the example of Lucius Aemilius Paulus and rationalistically explained to the troops that this was just periodic phenomenon that occurred when the Moon falls into the Earth’s shadow. But instead Drusus preferred to take a different tack, and after the eclipse occurred, explained that this was a sign that the gods had been horrified by their crimes. Stunned by what they had witnessed, the mutiny quickly dissipated.

Now, astrology seems to have taken hold among the plebeians not too long after cultural ties with the east deepened in the 2nd century BC. Among the aristocrats it took somewhat longer for it to be viewed as something that they themselves deeply believed. The first aristocrat we could perhaps call a true believer was Gnaeus Octavius who was consul in 87 BC. This was around the time of a civil war called the Social War during which the generals Cinna and Marius marched on Rome. Octavius had the opportunity to flee the city as the generals laid siege, but his astrologer advised him that he would survive if he remained where he was. So Octavius stayed, but when the generals took the city he was executed. Another player in this conflict, the general Sulla, also took astrology seriously. Although he was generally skeptical of divination, he appears to have encountered some astrologers in his campaign against Mithridates in the East. He came home with his horoscope which predicted, among other things, the date of his own death. Towards the end of his life, Sulla used this date to decide when to write his memoirs. Not too early so that he wouldn’t have to leave out the last part of his life, but also not too late so that he wouldn’t have time to finish it.

About a generation later a Roman senator by the name of Nigidius Figulus became well known for the breadth of his astrological knowledge, along with other mysticism and esotericism, chiefly of the Pythagorean variety. Nigidius had something of a middling political career. In the chaos of Caesar’s seizure of power, Nigidius ended up in exile and died before Caesar could extend him a pardon. But he was one of the great Roman politician scholars of the late Republic. He is less well known to us today than his contemporary Cicero, but that’s probably mostly due to the obscure subject matter he wrote about rather than the quality of his scholarship. Nevertheless, we have him to thank for our knowledge of the Babylonian and Egyptian constellations. One of the works he wrote was on what he called the two spheres: the Greek sphere and the barbarian sphere. The Greek sphere was the usual set Greek constellations that more or less map on to our modern day constellations. The barbarian spheres were then the constellations according to the barbarians, and here Nigidius had in mind the Babylonians and the Egyptians. Well one story about Nigidius’s astrological skill comes down to us. It’s said that one day in 63 BC the Senate was meeting, September 23 to be precise. The Senate was conducting its business as normal when after a while a senator named Gaius Octavius rushed into the chamber. He apologized to his colleagues for his tardiness and gave the excuse that a son of his had been born that morning. Immediately Nigidius recognized the significance of the time of the child’s birth and stood up and proclaimed that this child would become the master of the world. And indeed the child would grow up to be none other than the emperor Augustus. As good a story as it is, it’s almost certainly apocryphal since as I mentioned two episodes ago, the Roman calendar was identical every year and the Senate did not meet on September 23.

Now, ever since the second century astrology had been rising in popularity, quickly among the masses and somewhat more slowly among the patricians. But if we are to identify a single point in time in which astrology became officially embedded in the Roman state and psyche, it was after the death of Julius Caesar in 44 BC. Now Caesar himself was generally skeptical of astrology and would routinely ignore the advice of astrologers. He was warned by the astrologer Spurinna, for instance, that if he and his armies crossed into Africa in 46 BC before the winter solstice, he would be met with disaster. Caesar ignored him, crossed into Africa anyway and had a very successful campaign. But people tend to forget that little hiccup of Spurinna’s. Instead they tend to remember a more successful prophecy of his that Caesar would die by the Ides of March in 44 AD. When the Ides of March had come and Caesar was still alive, no worse for wear, he was walking to the Senate and saw Spurinna and said, “Well, the Ides of March have come.” Spurinna replied, “Yes, but they have not gone.” Caesar, of course, was assassinated in the Senate shortly thereafter.

Without getting too deep into the politics of the time, the conspirators who had plotted Caesar’s assassination seem to have badly misjudged popular opinion about the dictator. They were expecting to be greeted with praise for having rid the people of this tyrant. But Caesar was fairly popular among the people and his death only served to augment his popularity. But what really seems to have cemented Caesar’s reputation in the eyes of the people as one of the greatest Romans was that four months later, during his funeral games in late July, a comet appeared in the sky. By all accounts this comet was tremendously bright, bright enough to be seen during the day, which makes it one of the brightest comets on record.

Now as I mentioned last episode, comets in antiquity were almost universally seen to be harbingers of doom. But Caesar’s comet seems to have been an exception, at least in Rome. The Romans interpreted the comet as bearing the soul of Caesar into the sky, and this interpretation was encouraged by Caesar’s adopted nephew and heir Augustus. Augustus used the arrival of Caesar’s comet as the launchpad for his political career, playing up the idea that Caesar’s rise had been destined by the heavens, which, with him as Caesar’s heir, by implication meant that he was destined by the heavens for great things as well. From this idea that Caesar was placed among the stars, catasterized, to use the technical term, courtiers of the time began referring to the emperor and members of the imperial family as “stars,” and this seems to be the origin of the usage of “star” that we have today for someone who is notable in a field like a movie star or a rock star.

Now although Augustus tried to portray his rise as inevitable, commanded by the stars, it was in reality anything but, of course. Augustus’s principal conflict was with the general Mark Antony. In the years after Caesar’s assassination, Mark Antony ended up with control of the Roman East and set up shop in Alexandria. Over the years respectable Romans at home began to gossip, first in whispers and later more loudly that Mark Antony had gone native. He had abandoned his Roman culture and succumbed to the decadent ways of the East. Now there’s two sides to every tale and Mark Antony’s adoption of local customs probably factored into his popularity in the East. But Augustus knew that if he wanted sole control over all of Rome he had to do something about Mark Antony. To shore up his popularity at home, Augustus pacified the people by throwing lavish games, handing out free food, paying for free haircuts and shaves, making the baths free. That was the carrot. One of the sticks he employed was to rid Rome of any subversive elements. And the astrologers of Rome had largely come from the East and so were generally on Mark Antony’s side. So in 33 BC Augustus had all astrologers expelled from Italy. Now this wasn’t actually the first time that astrologers had been expelled from Rome. I neglected to mention earlier that in 139 BC, about a century earlier, the Roman Senate voted to expel astrologers from Italy as well. The reason the Senate gave at the time was that “through their lies by means of fallacious interpretation of the stars they were fomenting in instable and shallow minds an ardor from which they themselves profited financially.” But the subtext of this earlier expulsion was that conservative elements in the Roman Senate were by this point getting worried about the growing influence of Greek culture on Roman society, which at this time had been going on for about a decade. Astrologers weren’t the only one’s affected by this decree, philosophers among others were expelled, too. They had 10 days to pack up their bags and leave.

These kinds of expulsions were always temporary. In the first expulsion of 139 BC the prohibition expired after a year. And Augustus could ease up once he had eliminated the threat of Mark Antony. Later in his life, though, Augustus imposed an edict which would have a profound effect on Roman astrology and politics. In 11 AD Augustus issued a set of regulations on the practice of astrology. These were not limited to Rome or Italy itself, but applied to the entire empire. The most important pieces were first that astrologers had to conduct sessions with two clients at a time — they could not meet one on one with someone. And second, they were forbidden from predicting the date of anyone’s death. Now, these two rules might seem a bit anodyne at first glance. But they were a big deal in practice. These regulations were the basis for dozens and dozens of trials, convictions, exiles, and executions that we have records for, some of which were very high profile. And undoubtedly there were hundreds or thousands of lower profile convictions that we do not have records for.

At one level, these rules were about maintaining social order. A son who learned from an astrologer that his father was soon to die might want to help the process along so that he could receive his inheritance sooner. Suppose the predicted day came and the father was still puttering around — his son might take things into his own hands to make the prophecy work out. Or, even if he didn’t go to quite those extremes, it’s easy to see how it might lead to other problems. Perhaps he’d just start taking things a little early. After all, if the father was going to die in a few months anyway, what’s the harm? Or a husband who learned that his wife was going to die shortly might want to start looking for a new woman to replace her sooner rather than later. The other requirement, that any astrological consultations have two people present, excluding the astrologer, was a kind of enforcement mechanism. Now you’d have another person who could potentially snitch on you and this would act as a incentive to keep your conversation with the astrologer on the up-and-up. But from Augustus’s perspective, any improvement to the social order from these regulations was probably just a nice bonus. What he was really interested in was making sure that no one predicted the date of his death. Trying to determine the date of the Emperor’s death was not just any old crime. Since the Emperor effectively was the state, trying to determine when he would die was treason.

And it’s easy to see why. The Emperor needed to ensure that his authority was absolutely unquestioned. We’re all familiar with the idea of a lame duck in American politics, in the months after an election when a new president or Congress has been voted in. Officially the old president or party is still in charge. But in practice it’s hard for them to get all that much done because everyone knows they’ll be gone in a few weeks time anyway. So in Rome, if everyone started to believe that the Emperor would die within a few weeks, well, why would anyone listen to him? Now you might say, what’s the big deal here? Just wait a few months and when the Emperor is still fit as a fiddle everyone would realize the prognostications were wrong and move on. No harm no foul. But the main issue is that these kinds of predictions had a way of turning into self-fulfilling prophecies. Roman emperors ruled by fear as much as anything else. No one wanted to be caught appearing to be disloyal. That was how you found yourself dead in a hurry. Nearly every Roman administration was beset by conspirators who attempted to assassinate the emperor and seize power for themselves. Many of these conspiracies were buffoonish, but they were successful often enough to make them a real concern for every emperor. Augustus must have frequently thought of the fate of his adopted uncle Julius Caesar and how he could avoid dying in the same way. So conspiracies were dealt with ruthlessly. This posed a kind of prisoner’s dilemma for the conspirators. A successful conspiracy needed quite a few people involved in order to gain access to the Emperor in a way that could cause him harm. If they all kept their mouths shut they could possibly succeed and end up with greater power in the new regime. But if one of them defected and spilled the beans to the Emperor, that one could be assured high honors for having saved the Emperor’s life. The rest would be dead. So you can see how an astrological horoscope that predicted that the Emperor would die shortly would be incredibly valuable to a nascent conspiracy. If you learned of a brewing conspiracy and you also know that the Emperor is soon going to die, it would be a really bad idea to defect. After all, the horoscope is basically telling you as clear as can be that the conspiracy will be successful. Being seen to betray the conspirators is going to look really bad when they end up in charge.

So these kinds of astrological predictions were of tremendous political importance in the Roman Empire. From Augustus onward, every Roman emperor to a man was a firm believer in astrology, at least up until sometime after Constantine when the emperors were largely Christian.

Now when Augustus issued this edict he had to be very careful that this itself didn’t pose a danger to himself. After all, if there are rumors flying around that the emperor is going to die soon, and then the Emperor issues a decree forbidding predictions of the date of the Emperor’s death, well, that looks a little convenient doesn’t it? So simultaneously, Augustus also released his own horoscope, which included his own predicted death date. And good news for him, this date happened to be well into the future.

Now it should also be said that one of the perhaps unintended consequences of the various restrictions that the Roman government imposed on astrology over the years was that it legitimized it in the eyes of the public. After all, why would the government be getting so worked up about what the astrologers had to say unless there really was something to it? The more that astrologers were persecuted, the more popular and influential they became. One Roman author wrote that they were “a class which will always be proscribed in this country, and yet always retained.”

The earliest prosecution under the edict of 11 AD that we have record of was 5 years later of Scribionus Libo Drusus in the year 16 AD. By this point Augustus had died and the new Emperor Tiberius had been in power for two years or so. Tiberius was seemingly still a little bit insecure in his hold on power so at least in some accounts he manufactured a conspiracy in order to expose it and punish it, in order to make anyone else think twice. Tiberius chose Scribionus Libo Drusus as the target. Libo Drusus in these tellings was not a serious threat to the emperor. He wasn’t even really a serious man at all. He was a young man who was apparently something of a cad and was loose with his money. Libo Drusus at some point went to an astrologer to learn if he would be rich and he learned that indeed he would be rich enough to pave the Via Appia road with money as far south as Brindisi. Now, strictly speaking, Libo Drusus wasn’t breaking any rules here. True, if he really did become that wealthy, it did seem to imply he had to become Emperor because who else could be that wealthy? But the prohibition from the 11 AD edict was only against predicting the emperor’s death, which it doesn’t seem that he did. So Tiberius in order to prosecute Libo Drusus, he had to bend the rules somewhat. First, in order to get secure testimony about Libo Drusus’s treason, he had his slaves tortured to extract confessions that he wanted to hear. But even this was not enough because in Roman law, a slave could not testify against his master. So Tiberius forced the sale of the slaves to the state, whereupon their testimony became valid evidence since they were no longer his slaves. Furthermore, Tiberius prohibited the practice of astrology throughout Italy. Any Roman citizens caught practicing astrology would have their property confiscated and any foreign astrologers would be executed. At any rate, poor Libo Drusus saw the writing on the wall and before his trial committed suicide. His property was confiscated by several senators who were allies of Tiberius, and from that point forward, no member of his family was permitted to take the name Drusus and the day of his death was declared a public holiday. This story comes to us largely through Tacitus and at least in his telling, Libo Drusus was no kind of threat to Tiberius. But we do also have to leave open the possibility that Tacitus was biased and left out key elements of the story and that perhaps Libo Drusus was organizing a more serious conspiracy than we know.

But one thing that is certainly representative of this story for astrological prosecutions in the Roman Empire in general is that you’ll notice that the focus of the prosecution was on a Roman aristocrat. The astrologer himself who counseled Libo Drusus did not play much of a role in the trial. Today if someone is caught buying drugs, we usually expect the drug dealer to receive a much harsher sentence than the buyer. But in Rome the dealers of astrology so to speak tended not to be prosecuted as harshly as the buyers. Clients of astrologers were frequently executed. But astrologers themselves would generally be exiled or sentenced to a period of hard labor in the mines. Death sentences were typically only imposed on astrologers who openly predicted the date of an emperor’s death. The focus on the clients of astrologers rather than the astrologers themselves made sense in the Roman context though. The Roman emperors weren’t actually trying to stamp out astrology altogether. They knew that was impossible. They just wanted to prevent any challenges to their power. And the astrologers themselves were nobodies. They weren’t a threat to the throne. But their aristocratic clients were. They were the real danger, so they were the focus of prosecutions and the recipients of the harshest punishments.

Now it’s perhaps ironic that one of Tiberius’s first acts was to prohibit the practice of astrology in Italy because Tiberius was not only a true believer in astrology, one of his closest advisors was an astrologer and he was an experienced practitioner of astrology as well. To understand how Tiberius’s relationship with astrology developed, it’s worth backing up a little bit to the time before Tiberius took power. He had been a promising youth born into a notable family and as he came of age he was granted the position of quaestor. At the age of 21 he became an officer in the legions that went east to fight against the Parthian Empire and he conducted himself well. Not long after he married a noblewoman named Vispania and by all accounts the two were deeply in love with each other. But things started to go off the rails for Tiberius a few years later. The emperor Augustus liked what he saw in Tiberius and wanted to forge a closer tie to him. So Augustus requested that Tiberius divorce his wife and marry Augustus’s own daughter, Julia. Now calling something like this a “request” is maybe downplaying it a little bit. What would be the consequences of refusing the Emperor this request? Best not to think of it. So Tiberius complied. But Julia was not a great match for him. Julia had reputation for debauchery and licentiousness, and at least according to the rumors would go down to the Forum every night to drink and sleep with a new man.

After five years of this public humiliation that Julia caused him, Tiberius could take it no more and announced that he was retiring from public life and moved to Rhodes. At least that’s one version of the story, that Tiberius was motivated to move to Rhodes in order to escape the stain of his second wife on his reputation. But other motivations have also been proposed. He might have seen himself as being a back-up to take the throne if Augustus died, but once Augustus’s grandsons Gaius and Lucius came of age, they were the heirs to the throne and Tiberius wasn’t really relevant to the line of succession anymore. At any rate, what we do know is that in 6 BC, Tiberius gave up all the power he had acquired and moved to Rhodes, which, at that time was the center of Greek scholarship. In Rhodes Tiberius was very interested in spending his time learning philosophy from the masters. But he had a hard time fitting in in his new environment. Satirists in Rhodes mocked him as being an exile and the philosophers didn’t really want him around. And anyway he had no power anymore, so what was he going to do about it? One of the most prominent philosophers in Rhodes, Diogenes, went so far as to forbid Tiberius from attending his lectures.

It was here in Rhodes, rejected by everybody, all alone in the world, that Tiberius fell in with an astrologer named Thrasyllus. One apocryphal story has it that Tiberius consulted numerous astrologers to learn about his future and killed each one afterwards in order to keep the secrets of his future safe. But when he encountered Thrasyllus, Thrasyllus told him that he had seen in the stars that his own life was in mortal danger. Tiberius was so impressed by Thrasyllus’s skills that he kept the astrologer alive and had had him teach him everything he knew. Well, however the two came across each other, unlike everyone else in Rhodes, Thrasyllus was more than happy to spend time with Tiberius and teach him astrology, and by all accounts the two became close friends. We don’t know much about the early life of Thrasyllus or even where he came from. He may have been of Egyptian extraction but that is not much more than speculation. At any rate, the two spent a great deal of time together for about a decade in Rhodes. But then, catastrophe struck Augustus. In 2 AD one of his grandsons, an heir to the throne, died of an illness and then in 4 AD his other grandson died, probably from an infected wound, leaving Augustus with no heirs. All of a sudden, Augustus’s carefully lain succession plans were shattered. Tiberius was once more the only man Augustus could turn to to take over the empire after his death. So shortly thereafter Augustus summoned Tiberius to return to Rome and reenter public life. Before he had heard any of this, Tiberius claimed to have seen in the stars that a ship that would bring him good fortune would soon arrive.

Well, regardless of the merits of that particular story, what is known is that when Tiberius returned to Rome, he brought Thrasyllus with him and Thrasyllus jumped headfirst into the cutthroat politics of Rome. Now, Augustus was old when he recalled Tiberius back to Rome, but he was by no means out of power. But Thrasyllus seems to have made a good impression on the emperor. There is a story that Thrasyllus was a guest at one of Augustus’s dinners. At one point Augustus improvised some lines of Greek poetry. Then he turned to Thrasyllus and asked him if he could name the author. Thrasyllus said he did not know. So the emperor improvised another line or two then asked Thrasyllus if he knew now. Thrasyllus wisely responded that he still did not know who the author was, but whoever wrote it, the verses were very good.

Well Thrasyllus was undoubtedly closely involved in Augustus’s 11 AD edict that prohibited the determination of death dates and was probably also the one responsible for the Augustus’s own horoscope that he published. It’s also probably around this time that Tiberius managed to obtain Roman citizenship for Thrasyllus, which, at time was not easy for a foreigner to obtain. But after Augustus’s death in 14 AD, Tiberius took over and Thrasyllus’s status attained new heights. Tiberius arranged for Thrasyllus to marry a woman named Aka who was a princess of the Kingdom of Commagene, one of Rome’s client kingdoms to the East.

Astrology continued to play an important role throughout the entirety of Tiberius’s reign. One story has it that Tiberius had a dream in which a certain man told him to pay him some money. When Tiberius awoke he meditated on the dream and its meaning for some time and then had the man that appeared in his dream executed. Tiberius reasoned that this was clearly a magic trick. The man was testing Tiberius with something small, just giving him a little bit of money. But if Tiberius acquiesced to that request, he surely would acquiesce to more substantial demands in the future.

Well, during Tiberius’s reign there were a number of other high profile convictions of aristocrats violating the proscriptions on astrology. In the interest of time I won’t go into all of them. For the most part, if you’ve seen one you’ve seen them all. At least from the records we have, they seem to have been largely trumped up charges meant to eliminate any potential rivals or just generally cow the aristocratic class. Roman emperors used fear quite effectively to maintain their power. The emperors had networks of what we would today call secret police who would try to root out disloyalty throughout the empire. You might be sitting in a popina, a Roman tavern, enjoying a drink, when a stranger would sit down next to you and start loudly complaining about the latest buffoonery of the emperor. Perhaps he was just a simple citizen with a grievance who wanted to vent. But he could also be an agent of the emperor looking for sedition. Agree with him about the foolishness of the emperor a little bit too enthusiastically and you might wake up the next day in a prison being charged with treason.

At any rate, Tiberius outlived Thrasyllus, but not by very long. In fact, not long before Tiberius’s death, Thrasyllus predicted that the emperor would live another 10 years. In fact Tiberius died about two years later, and Thrasyllus shortly after that. Now as it happened, Thrasyllus’s son, Balbillus, also decided to go into the family business and became an astrologer, as well. Given the connections to the Roman aristocracy that Thrasyllus had developed, Balbillus had the foundations for a very successful career as an imperial astrologer, and perhaps as a consequence of growing up in the midst of it all, he also happened to be quite adept at navigating the treacherous Roman politics of the day. After Tiberius died and his more unhinged successor Caligula took the throne, Balbillus wisely decided to skip town for a little while and puttered about in Alexandria. After Caligula died and Claudius took the throne he returned to Rome. The relationship between Balbillus and Claudius somewhat resembled that of Thrasyllus and Tiberius. Thrasyllus had befriended Tiberius when Tiberius was at a low point in his career and really had nothing to offer in return. Tiberius remembered that and always treated Thrasyllus well thereafter. Similarly, Claudius had been born with some disability, partly physical, and possibly mental as well, the historical record isn’t exactly clear. In ancient Rome, this essentially removed any possibility of him having a political career. Once it was clear as a child that he had whatever disability it was, he was more or less ignored by his family. It seems he ended up spending a fair amount of time in the house of Thrasyllus since Thrasyllus was such a good friend of the imperial family, and there he came to know and befriend Balbillus as a child. So, once again, the kind treatment that Balbillus showed to Claudius when Claudius had nothing to offer them in return was repaid in spades when Claudius donned the royal purple.

Claudius appointed Balbillus to a number of important posts, some of which were really quite remarkable given that Balbillus wasn’t of Roman ethnicity, though he was a citizen. During the invasion of Britain, Balbillus was appointed the head of the engineering corps and performed admirably in that role. Later on Claudius appointed him high priest of the temple in Alexandria, overseer of the imperial buildings in the city, and, most prestigious of all, head of the Library of Alexandria. For his part, Balbillus helped Claudius avert a potential disaster. He noticed that an upcoming solar eclipse was going to occur on Claudius’s birthday. If this had caught people by surprise it clearly would have been interpreted as a terrible omen. To nip it in the bud Claudius publicized the date and duration of the upcoming eclipse well in advance to prove to his people that not even the heavens could take him by surprise.

But the next major astrological event occurred during the reign of the subsequent emperor, Nero. In the year 64, a comet appeared in the skies. As always, at least excepting Caesar’s comet, this was interpreted as an omen of doom, typically auguring the death of an emperor. Not good news for Nero. But Balbillus presented Nero with a way out. This comet augured doom, yes, but it didn’t necessarily have to augur doom for him. If Nero proactively executed a large number of aristocrats, that would indeed fulfill the comet’s omen, the death of lots of aristocrats being astrologically equivalent to the death of one emperor. Nero found Balbillus’s advice to his liking and executed that plan, and the aristocrats, with gusto. It is perhaps ironic that one of the means by which Nero effected his purge was by convicting people for violating the regulations around astrology.

It’s no surprise that Nero’s persecution of the aristocracy did not exactly endear him to them. Relations between Nero and the aristocracy had always been poor, but after these purges they descended into a spiral of violence. Despite Nero’s desperate attempts to prevent it, rumors from the astrologers about Nero’s impending death swirled and four years later he killed himself during a coup.

Nero’s death then ushered in a period of civil war known as the Year of the Four Emperors, in which a number of generals vied for control over the now leaderless empire, four of whom were successful enough to claim to be emperor, at least briefly. In these chaotic times astrology played a yet more important role than before. Who was going to be emperor, what would the future bring? There was no way to tell except by consulting an astrologer. The first of the four to claim the title of emperor, a general named Galba, had a plausible astrological claim to the throne. You’ll recall that Tiberius was himself proficient at astrology. Early in his rule, Tiberius at one event met a number of aristocratic youth, among whom was Galba when he was a boy. Knowing Galba’s birthday, Tiberius recognized that the boy possessed an imperial horoscope. Now, ordinarily, this would mean that the boy was a threat and would probably have led to his demise. But Tiberius saw in his horoscope that the boy would become emperor only late in life and then only briefly, so he posed no threat to Tiberius. So when Tiberius met the boy he pinched his cheek and said, “One day, child, you will taste a little of my power.”

Well, indeed Galba did become emperor late in his life and ruled only briefly, about six months, before he was assassinated, whereupon Otho took the title of emperor. Now, unlike the other contenders to the throne who were generals, Otho was more a creature of the Senate and Roman politics. Being from that milieu he had the support of the astrologers in Rome, who, after all, depended on the Roman aristocracy for their livelihood. So as his competitors, the generals Vitellius and Vespasian approached Rome with their armies, those generals found themselves on the wrong side of astrological forecasts. Now, Vitellius was quite superstitious and frequently consulted diviners, but he made an exception for astrology, which he had little respect for. As an infant his parents had had his horoscope cast and found that it harbored doom, and they tried, unsuccessfully, to keep him away from positions of prominence in Roman politics. So, it’s no wonder, then, that the ambitious Vitellius preferred to believe that astrology was bunk. As Vitellius marched on Rome, to avoid the embarrassment that the astrologers were causing him by predicting his imminent death, he decreed that all astronomers be banished from Rome, effective October 1, 69 AD, giving them a few months to pack up and scram. In response, a number of astrologers put out defiant placards that stated that they weren’t going anywhere because Vitellius would not survive to October 1. In the course of the next few months it seems that Vitellius executed any astrologers he could find in Rome, but the records don’t indicate precisely how many that was. As it happens, the astrologers were wrong, but not by much. Vitellius was assassinated in December of that year and the fourth emperor in the year of the four emperors, Vespasian, took power.

Now, throughout all this chaos, Balbillus had wisely made himself scarce. There was no sense in publicly allying himself with an emperor if that emperor was likely to be overthrown by a rival in a few months. Balbillus seems to have ended up in Ephesus where he maintained a low profile. But once Vespasian’s claim to the throne appeared to be secure, he returned to Rome to fulfill all the Emperor’s astrological needs. By now, Balbillus had outlasted six emperors and he was able to ingratiate himself with the seventh. Balbillus seems to have had a good relationship with Vespasian. Because of Balbillus’s residence in Ephesus, Vespasian granted the city of Ephesus the rare honor of being permitted to celebrate the sacred games, which ordinarily could only be done in Rome. Nevertheless, Balbillus was unable to prevent his mother’s homeland, the Kingdom of Commagene, from being converted from a client kingdom into an ordinary Roman province. But he did at least manage to secure asylum in Rome for the royal family after they did battle with the Roman legions sent to enforce this order.

The main astrological event of Vespasian’s rule was a comet that appeared in 79 AD. Perhaps counseled by Balbillus, Vespasian didn’t take it too seriously. “Comet” in Greek literally translated to “long-haired star,” so Vespasian joked that it was clearly more of a threat to the long-haired king of Persia and not himself since he himself was bald. But nevertheless, Vespasian did die later that year.

Balbillus then survived the next emperor, Titus, who ruled for two years before dying of some illness, though rumors were always whispered that he had in fact been poisoned by his brother, Domitian, who succeeded him to the throne. Sometime during Domitian’s reign, probably earlier rather than later, Balbillus died, and the tremendous influence he and his father had been able to wield by providing astrological advice to the throne throughout almost the entire first century came to an end. In addition to his political influence, which comes down to us through later Roman chroniclers, Balbillus also wrote an astrological treatise. Summaries of it survive along with a few fragments. Unsurprisingly, the main focus of the text is on predicting when a person will die. There is a rather amusing manuscript that almost provides some details about Balbillus’s astrology but then decides better of it. The scribe apparently had planned to write a chapter about it, which he entitled “What I found useful in the work of Balbillus.” But then he seems to have had second thoughts after reading through Balbillus and just wrote down “This chapter has been omitted as useless.”

Anyway, the death of Balbillus by no means meant that Roman emperors suddenly stopped being interested in astrology. Domitian, in particular, was a ruthless ruler and to protect himself, proactively sought out nobles who had horoscopes he believed to be regal and had them executed. But the thing that troubled him most was his own horoscope. An astrologer, named Asclation had predicted that he would die on September 18, 96 AD at noon. Needless to say, as the day approached, this prediction caused Domitian some anxiety. The day before his predicted death, he brought Asclation before him and asked him whether or not he still believed that he would die the following day. Asclation replied that indeed he would. Domitian then had an idea. He asked Asclation what the manner of Asclation’s own death would be. Asclation replied that he had seen in the stars that he would be torn apart by dogs. So Domitian ordered the astrologer to be immediately burned at the stake. Asclation was tied to a stake in the Roman streets and a bonfire was lit underneath him. But just as the fire was growing, a sudden downpour quenched the fire and the Roman soldiers ran to get out of the rain. In the soggy mess, the stake holding the half-burnt Asclation tipped to the side, and lying helpless in the street, a pack of dogs came upon the astrologer and tore him to pieces. Needless to say, the reports of this event did not ease the anxiety of the emperor.

The following day, the day of his prophesied death, Domitian was distressed and became more and more so until noon approached at which point he was a nervous wreck. Sometime around noon, however, he asked an attendant what the time was. The attendant lied to him and gave him a time that was a few hours later. The danger had passed. Immediately Domitian was filled with relief. He decided to take a bath, presumably to wash away the nervous sweat that he had been dripping in all day long. As he was happily on his way out, a court official named Stephanus came in and asked for his signature on a few documents. Stephanus had had an arm injury the past few days and had his arm was in a sling. Or so it seemed. In fact, Stephanus’s arm injury was all a ruse. He was a member of a conspiracy trying to assassinate the emperor, as was the attendant who lied about the time. Stephanus’s sling concealed a dagger and when he got close to the emperor, he pulled it out and stabbed Domitian to death.

Now, when we hear these kinds of stories, it’s worth asking did they actually happen? Of course, we cannot say for sure because we’re relying on the accounts of Roman historians who oftentimes were more interested in telling a cracking good story than dispassionately conveying events as they happened. But the story is more plausible than it might seem. I mentioned at the outset that astrology in the Roman empire had so much power precisely because people believed it. It had a way of becoming a self-fulfilling prophecy. We know that it was common for astrologers to predict the exact date of the death of an emperor. In fact, that was one of their main jobs, even if it was illegal. Now, of course, a priori, Asclation could have had no way to know when the Emperor would die and pulled the date September 18 out of thin air. But once Domitian’s horoscope was known in court circles, that acted as an anchor point for any conspiracies against the emperor. After all, if you’re going to conspire to assassinate the emperor, you’d better have the stars on your side. So the conspirators may have used that date to determine the timing of their plot.

Well, I can’t hope to cover the entirety of Roman history in a single episode, so I’m going to skip ahead a few emperors to Hadrian, who was, along with Tiberius, the other astrologer-emperor. Hadrian’s journey with astrology began not long after he was born. His great-uncle, who also had an interest in astrology, declared that the boy had an imperial horoscope. And if you recall last episode I went into a bit of detail about what that specifically looked like. The main feature was that Jupiter was in its heliacal rising, or nearly so anyway, the Moon was in conjunction with the Sun, and the other planets were bunched around them in a sort of regal procession. Hadrian was a bookish youth and perhaps due to his auspicious horoscope he seems to have developed an interest in astrology at a young age and read whatever he could on the subject. For his first official post he was sent to the frontier out at the Danube river and while there he came into contact with a local astrologer who verified the portent of his horoscope. Throughout his life, at the start of every year, he would read the stars to forecast what would happen to him in the upcoming year. If you’ve ever read God Emperor of Dune I can’t quite help but feel that there is a parallel here. No doubt there was an element of propaganda in this story — don’t even bother trying to overthrow the emperor because he’s already foreseen your actions months in advance.

One of Hadrian’s most lasting impacts on the heavens came about due to the death of his lover Antinous. Hadrian had been married to a woman named Vibia Sabina who was his second cousin once removed, but the marriage was political and Hadrian didn’t really care for her. But some years later, while on campaign out east, Hadrian met a young man, or possibly a teenaged boy, named Antinous. Hadrian evidently fell deeply in love with Antinous and from that time onward took him with him everywhere. About seven years later, Hadrian and Antinous were traveling down the Nile when Antinous drowned. The standard explanation is that this was an accident. But more salacious stories have it that Hadrian had Antinous sacrificed, possibly to avert danger that he had seen in an astrological omen. Either way, Hadrian deeply grieved Antinous’s death and fostered a cult to worship the young man. Hadrian pronounced that like Julius Caesar, Antinous had been catasterized — he had been placed among the stars as a small constellation just south of Aquila, the Eagle. And from thereon, the constellation of Antinous became frequently identified as one of the constellations of the night sky in Western Europe up until 1930, when the International Astronomical Union standardized the modern 88 constellations that are officially recognized today.

Hadrian’s faith in astrology may have been responsible for one other puzzling feature of his reign. Hadrian was always recognized as being one of the most competent of the Roman emperors. But historians have long wondered about the arrangements he made for his succession. Hadrian had no children of his own, so towards the end of his life, he needed to line up a successor so that Rome did not descend into civil war after his death. Out of a number of worthy candidates that Hadrian had available to him, he picked none of them, and instead chose a consul named Lucius Aelius Caesar who apparently only excelled at mediocrity. History has no definitive explanation for Hadrian’s bizarre choice, but one natural possibility is that he was motivated by astrology. Perhaps Lucius Aelius, despite what you might see with your own eyes, possessed an imperial horoscope that destined him for greatness. But if that is the case, Hadrian’s skills as an astrologer evidently failed him because Lucius Aelius, who had always been sickly, died a few years later, before Hadrian’s own death.

Well, astrology continued to play a role in the Roman Empire for another few centuries, really until the 4th century when the emperors converted to Christianity. As I’ve mentioned before, Christianity has always tended to have an adversarial relationship with astrology. It was always too popular, and, at least according to its adherents, too powerful a tool to completely abandon. But once Christianity spread, the nature of astrology changed. Christianity, as with Judaism, was incompatible with the fatalistic interpretation of astrology, where one’s destiny was written immutably in the stars. But I will have to save a more detailed discussion of the relationship between astrology and this new religion of Christianity for a future episode.

This month’s episode was mostly focused on the ways in which astrology interacted with Roman politics, but didn’t have to much to say about the astrology itself. Next month I will remedy that by looking at the one major Roman contribution to astronomy, though mostly astrology, which was an early first century text by an astrologer named Marcus Matilius called Astronomica. I hope you’ll join me then. Until the next full moon, good night and clear skies.

Additional references

  • Cramer, Astrology in Roman Law and Politics