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The Imperial Planets

Towards the end of the 3rd century BC Greek drama and literature began to seriously interest the Romans. At first, astrology crept in at the lower end of the social scale: while the intelligentsia were enjoying Greek plays and poems, hoi polloi was fascinated by the crowds of fortune-tellers making their way - as quacks always will - towards a new source of easy money.

But it was not long before, at first out of an interest in astronomy, intelligent Romans learned about the Greek preoccupation with the influence of the planets on humanity. By the 1st century BC, Cicero, always sceptical about astrology, took it seriously enough to summarize it without irony in his De divinatione:

In the starry belt which the Greek calls the Zodiac there is a certain force of such a nature that every part of that belt affects and changes the heavens in a different way, according to the stars that are in this or in an adjoining locality at a given time ... They believe that it is not merely probable, but certain, that just as the temperature of the air is regulated by this celestial force, so also children at their birth are influenced in soul and body, and by this force their minds, manners, disposition, physical condition, career in life and destinies are determined.

Cicero's summary of how astrology worked shows how the intelligent Roman understood the subject: he emphasized that normally only the twelve signs and planets were considered; that it was the ascendant, the rising sign appearing over the eastern horizon at the moment of birth, that was the 'natal sign' (not the 'Sun sign', which was not to become strongly associated with simplistic astrology until the 20th century); that the astrologer drew his conclusions from the angles between the planets as they were placed in the twelve constellations, and in the 'houses', each of which showed an influence in one area of the life of the subject - house four was that of the parents, house five that of children, house ten of honours and house eleven of friends.

We are not concerned here with the growth of the star cults among the Romans between 300 and 150 BC; but during those years various new divinities took up residence, among them Asclepius, Cybele, Bacchus, Isis and Mithras (to say nothing of Jehovah); they all, however, had to some extent astrological associations (even Jehovah), and contributed to a growth of serious interest in the subject. Mithras, especially, took that interest out into the Empire, making converts abroad: 'modern' astrology undoubtedly first reached Britain in the form of Zodiacal carvings at Mithraic shrines, while Asclepius became the patron saint of astrological medicine.

As is usually the case when a country is invaded by a new culture, some reactionaries took great exception to the changing times. But the tide was against them. Scipio Africanus, for instance, the conqueror of Hannibal, whose scandalous interest in things Greek was said to have persuaded him to go about in public in Greek dress, was a great upholder of philhellenism; and even the sceptical and strong-minded Cato, towards the end of his life, was injected with the new spirit, and started to learn Greek.

It was Cato who quite properly issued warnings about the innumerable quack astrologers and magicians coming to Rome in and around 200-150 BC. The poet Ennius, a southern Italian brought to Rome by Cato, attacked them too:

Of little use are these Marsian quacks,

Village-astrologers and fortune-tellers

In crowded circuses, or priests of Isis,

Pretend-interpreters of all your dreams.

These lying conjurers have not the skill

To read the future; just a pack of hypocrites

Prompted by hunger, they don't know themselves

Let alone others; yet they'll promise you

Enormous fortunes - if you'll share with them!

But the influence of the quack astrologers was far outweighed by the influence of the knowledge accumulated by Greek astronomers, and the Romans were enormously impressed by scientific achievements. When Marcellus conquered Syracuse in 212 BC, and returned to Rome with a magnificent model of the celestial spheres which he had found in the house of Archimedes (killed when the city fell), it was greatly admired - and used. And since the two terms were still synonymous (astronomia is sometimes used where we, today, would expect to find astrologia, and vice versa - Plato uses only astronomia, Aristotle only astrologia) this meant there was at the least increased pressure on intelligent Romans to look at the theory that the planets affected human behaviour.

A minority declined to be persuaded: Cicero, as we have seen, but also, a century earlier, the Greek sceptic philosopher Carneades. He was one of the heads of the Platonic Academy, and ambassador from Athens to Rome in 156.BC. He maintained that not only was it virtually impossible to make an accurate observation of the sky at the moment of birth (let alone conception), but that it was clear that astrology did not and could not work because people born at the same moment could have very different destinies, while others born at very different times and places died at precisely the same time; moreover, animals would have the same fate as human beings whose birth moment they shared, and people of different races, customs and creeds born at the same moment would obviously have different fates. He failed to see that his second and last objections cancelled each other out: most astrologers then as now made it quite clear that astrology was only one ingredient of a life, and environment and custom would certainly mitigate its effect.

Carneades' objections have been rehearsed many times since his first statement of them (among others, by St Augustine, who took them wholesale and used them as his own). They are on the whole not very convincing, although they had more significance at the time they were made, when some astrologers at least were highly fatalistic. And certainly they must have had an effect in Rome, where Carneades was sensationally successful as a lecturer - fashionable young Romans eager to keep up with Greek culture and fashion crowded the halls in which he spoke.

It would be a mistake to assume, then, that astrology had a walk-over. In 139 BC, an edict was actually passed enabling Rome to expel any foreigner who gave trouble; the arguments of Carneades were used to support the claim that astrologers were simply exploiting the credulous poor, and many of them were thrown out. The attitude of authority - that astrology seemed likely to cause trouble - was borne out in 134-2 BC, when there was a sizeable slave revolt in Sicily, led by one Eunus, who either was or gave an inspired imitation of being an astrologer. He was obviously a very accomplihed charlatan (if we are to believe the historian Florus, who says that among his tricks was the concealment of a nut full of sulphur in his mouth, which flamed with fire and smoke as he spoke), and with the aid of tricks and oratory commanded the force of over 60,000 slaves. Even when the rebellion was crushed, the Romans were sufficiently impressed with Eunus as a seer to capture him alive.

Less than thirty years later, Athenio, another astrologer (this time a serious one) led another slave revolt in Sicily; insisting that the planets had revealed that he was to be king of Sicily, he and his followers gave trouble until about 100 BC, when he was killed in a hand-to-hand fight with the consul Manius Aquillius.

The first real Roman astrological expert was one Publius Nigidius Figulus - not a mere nobody, but someone who held public office, as an aedile and later as praetor, or magistrate. His reputation as an astrologer was considerable, and he was at the centre of what was virtually the earliest Roman astrological school, and among other books published several on prediction and meteorology, as well as on pure astronomy. Alas, Julius Caesar, when he came to power, was unsympathetic, and banished him (although probably for political rather than astrological reasons).

The growth of public interest is illustrated in the work of M. Terentius Varro, a colleague of Nigidius Figulus - not himself an astrologer, but keenly interested in the subject as a means of clarifying history. He commissioned a horoscope of Rome itself and its founder, Romulus - the first example we have of astrology being used to reveal the past by examining the history of a person or place, and from this estimating the probable 'birth time'. Cicero reports that Lucius Tarutius of Firmum, a mutual friend, calculated that Rome was 'born' when the Moon was in Libra, and 'from that fact unhesitatingly prophesied our destiny'. Plutarch later reported Tarutius' findings in greater detail, suggesting that 'these and similar speculations will perhaps attract readers by their novelty and extravagance rather than offend them by their fabulous character.'

Varro, although not an astrologer, included a chapter on astrology in his De disciplinus which was so good and so economically expressed that it was used again and again by later writers. One of his friends seems to have been that C. Fonteius Capito who went' with Antony to the East, and played an important part in reconciling him, briefly, with Octavianus before returning to Egypt to travel with Cleopatra to Syria.

The sceptics were thinning out, and fighting a by no means successful rearguard action. Cicero remained unconvinced, even after a stay on Rhodes with the Greek Stoic Posidonius, and a close friendship with Nigidius Figulus. He seems to tolerate the idea of astrology in his On my consulate, but later unequivocally states his opinion that 'the condition of the heavenly bodies may, if you will, influence some things, but it certainly will not influence everything.' He was not silly enough to deny that the Sun influenced the growth of plants, or the Moon the tides, but was very doubtful about any effect the planets might have on human life. And still later, in his essay On divination, he pressed the attack, giving eight specific criticisms, including the old question of the birth of twins, the possibility of astrologers not being able properly to see the sky, and the effect of environment - also bringing in the fact that 'the parental seed' contributed to a person's appearance, habits and outlook, and that the new advances in medicine meant that 'natural defects' with which a child might be born could be cured. On divination is perhaps the coolest example of early Roman scepticism; another occurs in Lucretius' poem De rerum natura, in which he argues in favour of free will, and that the soul is as mortal as the body, and thus no celestial panacea is acceptable.

Among the myths perpetuated by some astrological historians is that representing Julius Caesar as a proponent of astrology, or even himself an astrologer. On the contrary, he seems to have been almost entirely sceptical, although he accepted the obvious planetary effect on weather and plant growth. Otherwise, he not only rejected old-fashioned omens, but at least two horoscopes presented to him by celebrated astrologers promising him a happy and peaceful death at the height of years of success. Perhaps the legends of his interest in the subject arose because of his choice of the symbol of the Bull as his legionary standard (Taurus is 'ruled' by Venus, and Venus herself was said to be Caesar's ancestress). Most likely, he chose this deliberately, pandering to the superstition of the ordinary soldiers. There seems to be no reason to reject the story that tells of his refusing to accept his wife Calpurnia's warning dream of the night before his death; and it seems, too, to be a fact that an astrologer called Spurinna warned him to 'beware the Ides of March'.

He seems to have known Spurinna quite well; he mentions him in his letters. It is also likely that it was this astrologer who, in 46 BC, had advised Caesar against crossing to Africa until after the winter solstice - advice Caesar rejected, and without catastrophe. Cicero knew him well, too, and scorned his abilities. Well, he was accurate enough when he warned Caesar that he 'should beware a danger which would not threaten him beyond the Ides of March', as Plutarch reported it; and Cassius Dio, the Roman historian of AD c 150-235, pointed out that here was a good example of the fateful nature of a firm astrological prediction.

At Caesar's death, a splendidly showy comet appeared, to blaze through the night sky for seven consecutive evenings; clearly he had become immortal, and was on his way to shine among the stars.

During his student days at Apollonia, when he was regarded as certain to be the next monarch, Octavianus Augustus had visited a well-known local astrologer, Theogenes, who, the moment he set eyes on Octavianus' birth chart, threw himself at the young man's feet. Unsurprisingly, Octavianus was extremely impressed, and (so Suetonius says) 'from that time on had such faith in his destiny that he made his horoscope public and issued a silver coin stamped with the sign of the constellation Capricorn under which he was born.'

At all events, Octavianus saw in the public reaction to the appearance of Caesar's comet in 44 BC the fact that astrology could be a fine implement of public relations. But only if it was on his side - and most of the astrologers in Rome at the time of Caesar's death tended to favour the fortunes of Antony, whose identification with the East (and indeed with Cleopatra) appealed to them. Octavianus made Agrippa (a lifelong friend who had been with him on that visit to Theogenes) aedile, and instructed him to expel from the city all astrologers and sorcerers.

He was no doubt right. By now, very few men at any level of intelligence or society contested the skills of the astrologers. Vitruvius, the great architect, reflected in his book the attitude of most people: everyone must, he said, accept the calculations of 'the Chaldeans', who could explain the past and future from astronomical calculations; He was completely assured that astrology worked, and as a science. Other authors of the time support this view: Horace, Virgil, Propertius, Ovid. And by now it appears that the Emperor Augustus (as Octavianus was proclaimed) shared it.

In the first place, he sought the advice of astrologers about a possible marriage for his only child, Julia. His stepsons Tiberius and Drusus were in their teens, and Julia herself only 16; obviously the sooner she was safely married, the better. The astrologers recommended Marcellus, Julia's first cousin. Consumptive and weakly, the boy died within two years of the wedding. The astrological advisers had better luck, of a sort, the second time. Advised by them, Augustus persuaded his friend Agrippa to divorce his wife and marry Julia. The marriage lasted eleven years and produced a clutch of possible heirs, although none of them in fact succeeded.

In 12 BC, Augustus once more ordered measures against the astrologers who had crept back into Rome during the past twenty-five years or so. Many of them were publishing predictions about the succession, some worryingly hare-brained. The Emperor passed a law submitting all prophesies to censorship; most of them perished in the flames before they reached the public.

Much of the astrological speculation hinged on a possible third marriage for the notoriously immoral Julia. Now, Augustus ordered his elder stepson Tiberius to divorce a much-loved wife and marry Julia. There was nothing Tiberius could do but comply - unless, of course, he chose suicide. A successful soldier, Tiberius managed to get away from Julia to go campaigning - gaining great honour. But when opportunities for this failed, and he could stand his new wife no longer, he asked Augustus' permission to retire to Rhodes 'to study'. The Emperor, who on principle disbelieved anything horrid he heard about his daughter, coldly agreed; so, in 6 BC, Tiberius went to Rhodes, and the general opinion was that, as a possible successor to the Emperor, he was finished.

Rhodes was a lonely place for a man straight from the centre of the Empire. Tiberius occupied his time gloomily attending classes given by local scholars, and at one of them met the man who was to become, with him, one of the two most important men in Rome: Thrasyllus, an Alexandrian grammarian, editor of Plato and Democritus, and an astrologer. There are various legends about the manner of that first meeting: that, for instance, Tiberius sought out many astrologers for their opinion about his future, killing them immediately they had interpreted his horoscope. Thrasyllus was the only one to comment on his own danger, which impressed Tiberius so much that he spared him. This is probably nonsense. But that is not to say that Tiberius was not impressed by Thrasyllus' first-rate mind, and it certainly seems true that he taught Tiberius how to set up and interpret a horoscope, and successfully predicted that he would soon be recalled to Rome and a bright future. When this happened - when Augustus sent for Tiberius in AD 4 and officially proclaimed him his heir - Thrasyllus travelled with him, and on reaching Rome received from his patron the valuable gift of Roman citizenship.

Ten years later, after a decade during which Thrasyllus ingratiated himself not only with his Emperor but with Roman society, Augustus died - his death accompanied, if we are to believe Cassius Dio, by a total eclipse of the Sun, a display of fire and glowing embers falling from the sky, and a number of melancholy comets. Tiberius was now Emperor, and Thrasyllus the power behind the throne.

Tiberius' reign lasted for nine years, and during it Thrasyllus was never far from his side. It is clear that he not only advised him on day-to-day matters, but about his close friends and the members of his family. By now, the astrologer had consolidated his status in Rome. His wife, who seems to have been called Aka, and to have been a minor princess of Commagene, had also been awarded Roman citizenship, and he had managed to arrange a Roman marriage for his daughter Claudia. Her husband was a Roman knight, L. Ennius, and they eventually had a daughter, Ennia Thrasylla, who was herself to become famous if not notorious.

Very few citizens of Rome during the reigns of the majority of Emperors were entirely free of fear, and Tiberius was by no means the least cruel or capricious. Thrasyllus was as safe as anyone; some other astrologers must have slept less comfortably. When in AD 16, Scribonius

Libo, a slightly dense praetor, attempted to organize a coup against the Emperor, and took the advice of two astrologers - L. Pituanius and P. Marcius - they were arrested with him; the first was thrown from the Tarpeian rock, and the second stripped naked outside the Esquiline Gate, his head fixed in a forked stake, and beaten to death.

Some other people suffered because of a mere interest in astrology. In AD 20, Aemilia Lepida, a woman of good family, once the fiancée of Augustus' grandson, was exiled for consulting an astrologer (although also on suspicion of trying to poison a former husband).

During the early years of Tiberius' reign a complex situation arose which Thrasyllus succeeded in riding like a wave. This concerned the Emperor's son Drusus, who seems (with reason) to have been jealous of Thrasyllus' influence with his father. When in the early 20s the Emperor's favourite, the praetor Sejanus, started a tempestuous affair with Drusus' wife Livilla, the lovers seem to have consulted Thrasyllus about their actions. Whether or not he played any part in the subsequent poisoning of Drusus, we cannot know. But Thrasyllus was left with the problem whether to support Sejanus or betray him and Livilla to the Emperor. There seems no question that the astrologer played a vital part in Tiberius' decision to leave Rome in 26, never to live there again; and this meant that Thrasyllus could maintain his influence with both Tiberius and Sejanus, supporting the latter in the battle for the succession which had arisen between him and Agrippina, Augustus' granddaughter, who wanted the throne for her children.

Sejanus, although rising higher and higher in Tiberius' estimation, continually sought to destroy opposition that might stand between him and the succession. He organized the trial of Agrippina and her son Nero for high treason, banishing one to Pandataria and the other to Pontia. And Thrasyllus further consolidated his position by marrying his granddaughter Ennia to Naevius Sertorius Macro, gaining another Roman knight as a close relative by marriage.

Whether Thrasyllus consulted the planets and was prompted by them to engineer a plot against Sejanus, or was simply consulting his own interests without astrological persuasion, he was certainly at the centre of such a plot; his son-in-law Macro not only carried the orders that destroyed Sejanus, but immediately took his place at the centre of Roman life, while Tiberius remained in self-imposed exile on Capri.

There, with him, lived Agrippina's younger son Caius; and it was this youth who now received Thrasyllus' support as successor to the throne. We know that Tiberius time and time again talked with his astrologer about the succession, and the evidence is that time and time again Thrasyllus persuaded him that the planets revealed that Caius could never succeed - that 'he had as much chance of becoming Emperor as he had of driving his racing chariot across the Bay of Baiae'. By this means he prevented the perverse Emperor from legally disqualifying Caius from the succession. What Caius felt about this is uncertain, except that we hear that he vowed that one of the first things he would do when he gained the throne would be to drive his chariot across the waters of Baiae.

Thrasyllus' relationship with the old, irritable and nervous Emperor was now extremely tricky. It is not easy to conjecture to what extent he honestly relied on his astrological knowledge, and to what extent concern for his own safety and that of his friends led him to equivocate. He did not hesitate to advise the Emperor to continue to trust the consul Servius Galba, for instance, although at his birth Thrasyllus had told Tiberius that Galba's horoscope showed signs that he would reach the heights of commanding power. Now, he reassured the Emperor that Galba's horoscope showed he would only become Emperor in old age - which meant Tiberius was probably safe from him. It is also clear that Thrasyllus could only advise the Emperor on the basis of genuine astrological calculations, for Tiberius himself was quite capable of these, and would have seen through any pretence.

This presents the problem of Thrasyllus' advice to Tiberius, given it seems in about AD 34, that he still had ten years of healthy life ahead of him. It has been taken for granted that Thrasyllus falsified the horoscope in some way, in order to prevent the ever-increasing number of judicial and non-judicial murders the Emperor was undertaking to protect himself against the ambitious. But Tiberius knew his own horoscope backwards; if Thrasyllus foresaw that he would in fact die within three years, he must have found some way of persuading his client otherwise.

In fact, Thrasyllus was to predecease Tiberius - although not before one final concern, when he learned that his daughter Ennia, on a visit to Capri, had started an adulterous affair with Caius, now fairly clearly the main contender for the throne after Tiberius' death. Macro, Ennia's husband, may or may not have known about the affair; he was by this time almost as unpopular as Sejanus had been at the height of his power, and neither his position nor Ennia's could have given Thrasyllus much comfort in the few months before his death - which he is said to have foretold to the hour.

Ironically, even after his death, Thrasyllus preserved the life of one of the earth's monsters, the Emperor Nero. Tiberius, continuing to ensure his own safety and juggle with the succession, had arranged several trials of alleged conspirators against the throne; and at the time of his death those a waiting trial included Domitius Ahenobarbus, the husband of Agrippina the Younger. When the Emperor died, Domitius was released from prison, and went home to his wife - who nine months later gave birth to the baby Nero. Had Thrasyllus not assured Tiberius that his life was safe for at least another decade, the trials would swiftly have been concluded, Domitius executed, and Nero would never have been born. (As it was, Suetonius says that the astrologer who calculated the baby's horoscope almost fainted away on contemplating its horrendous nature!)

Rome now had a new Emperor, Caius, who called himself Caligula. A considerable amount of carnage followed his accession, and among those who fled from Rome to avoid this was Thrasyllus' alleged son, Tiberius Claudius Balbillus. (Jack Lindsay, in Origins of astrology, 1971, argues that Balbillus was no relation of Thrasyllus; but we know that the latter's son was called 'Tiberius Claudius', and the relationship seems a likely one.) He settled in Alexandria, while his niece Ennia, whose lover was now on the throne, stayed to enjoy what seemed likely to be a position of considerable influence. Caligula is said to have given Ennia a written contract promising to marry her after becoming Emperor. If she relied on this, she was a less keen judge of human nature than her grandfather. Her husband Macro, who had done much to help Caligula to the throne, was killed on the Emperor's orders, and she apparently committed suicide. Not long after hearing of her death, Caligula married Lollia Paulina, who eleven years later was herself executed for consulting astrologers, allegedly to organize a coup against the Emperor Claudius.

Although Caligula continued to uphold the edict Augustus had laid down in AD 11, forbidding any astrologer to consult an Emperor's horoscope, his death was foretold by an Egyptian called Apollonius, who was hauled off to Rome and (according to Cassius Dio) sentenced to die on the very day he had said would be the Emperor's last. Foolishly, Caligula postponed the execution, the better to say 'I told you so'; but the Emperor died at the foretold time, assassinated on 24 January in AD 41.

Now Claudius became Emperor, and it was safe for Balbillus to return to Rome, for Claudius when a boy had been a constant visitor to Thrasyllus' house, and with an interest in intellectual matters uncommon in his family, had enjoyed hearing about literature and astrology, and enjoyed too the company of Balbillus, who he now received with enthusiasm. When in 43 he went to help conquer Britain, Balbillus went too, as an officer in the 20th legion - not only to give astrological advice, but to help run the engineers' corps. Claudius on his return to Rome was honoured with the title Britannicus; Balbillus received a crown of honour. He seems then to have split his time between Rome and Alexandria, for he was appointed high priest of the Temple of Hermes there, and also became head of the state university with its superb library (where he instituted an annual series of lectures in honour of Claudius, at which the Emperor's own works were recited).

Balbillus became, indeed, as respected a figure as his father - although he tried to keep clear of politics. The part he played in advising Claudius is obscure, but it is likely that he was behind at least one edict - that which announced, before the event, that there would be an eclipse of the Moon on one of the Emperor's birthdays. Much superstition still attached to eclipses, and it was wise to allay in advance any public fears that this one might be a malevolent omen.

Claudius was (no doubt encouraged by Balbillus) quite aware of the harm that could be done by intriguers who cared to use astrology to suggest good times at which to organize insurrection or even assassination. In 52, Furius Camillus Scribonianus was executed for alleged plotting against the Emperor; the evidence included a horoscope of Claudius found in his possession. Soon afterwards Claudius passed an edict, which, like the one in 16, banished all astrologers from the country. The very next year, one T. Statilius Taurus committed suicide after being accused of 'divination'. Two years later Domitia Lepida was accused of using black magic against Agrippina; astrology was mentioned at her trial, too (as at most similar trials).

Balbillus, like his father, found it impossible to avoid politics altogether, particularly the intrigues that now began to centre around the ambitions of two mothers - Agrippina the Younger, who wanted the throne for Nero, and Domitia, her sister-in-law, who wanted it for Claudius' son Britannicus. Agrippina had been told by Balbillus in 41 that Nero would be Emperor, but would murder his mother. This did not dissuade her, and pursuing her ambition she managed to marry Claudius, becoming his fourth wife (his third, Messalina, having met an unpleasant end).

Another astrologer now joined the court: Chaeremon, from Alexandria, known for his assertion that comets could presage joy as well as disaster. He was joined by the Stoic philosopher Lucius Annaeus Seneca, himself an adherent of astrology. The three were mainly responsible for the education of Nero. There seems little doubt that Balbillus took part in the extraordinary events after Claudius' death when Agrippina personally prevented Britannicus from leaving his room until, at an auspicious moment proposed by astrologers, Nero could be, and was, proclaimed Emperor. Balbillus was rewarded by being appointed Prefect of Egypt, where he stayed until 59.

Not long after his return, in 64, the fire that destroyed Rome while Nero allegedly played his fiddle spawned sufficient disCONTENT=to result in a plot to destroy the Emperor. When a spectacular comet appeared, Balbillus told Nero that it presaged disaster for him - unless he deflected its effects by executing some of the noblest men of Rome by way of sacrifice. In the following carnage Petronius, who had directed the entertainments at Nero's court, Seneca and his brother, his nephew the poet Lucanus, and many others perished. Balbillus did not. His success, if that is what it was, also made him secure against that dangerous rival astrologer, Ptolemy, the favourite of the new Empress Poppaea. Nero disposed of the rival by killing his wife in a fit of drunken pique. Balbillus retired quietly from the scene, vanishing from sight during the years when Nero died and Galba, Otho and Vitellius acceded and fell in their turn.

It was probably as well; it has always been said that among Nero's many victims towards the end of his reign were a number of astrologers - and certainly several Romans who had somehow got hold of the Imperial horoscope, for Nero supposed that the only reason for its possession was an assassination plot.

Galba, who succeeded Nero, had been told by Tiberius on the evidence of his horoscope that he would one day be Emperor, but he does not seem to have been uncommonly impressed by astrology. Otho is said by Tacitus to have plotted against Galba with the support of astrologers who 'urged him to action, predicting from their observation of the heavens, revolutions and a year of glory'. Ptolemy Seleucus positively ordered Otho to seize the propitious moment, and was proved right: Galba was successfully killed, and Otho ascended the throne. However, the Roman legions in Germany had proclaimed Vitellius Emperor, in the face of whose determined assault Otho crumpled, and killed himself.

Vitellius was not a follower of the planets, perhaps because the horoscope cast for him revealed that although he would become Emperor after a civil war, his reign would be brief. He continually said he did not believe this; and indeed it was a remarkable prediction to make, for there seemed little chance of its coming true. However, he did become Emperor (in 69), and although he expelled all astrologers by an edict passed a few days afterwards, and executed a number of them, he reigned only for three months.

During that short reign, Ptolemy Seleucus, who had got safely out of Rome, threw in his lot with Vespasian, plotting an uprising against Vitellius. Despite the fact that a comet appeared and two eclipses took place (to say nothing of the fact that several people saw two suns in the sky at the same time) Vespasian succeeded in becoming Emperor. This was a good time for Balbillus to return from self-imposed exile, for he and Vespasian had been on good terms since they met at Nero's court (where Vespasian endeared himself to posterity by falling asleep during one of Nero's recitations, a comment that happily escaped the Emperor's notice).

Vespasian was as devoted to astrology as some of his predecessors. On the evidence of Cassius Dio, he 'consulted all the best of them', and not only showed special interest in what Balbillus had to say, but allowed games to be held at Ephesus in the astrologer's honour - the Great Balbillean Games were held until well into the 3rd century. He trusted Balbillus, and indeed Ptolemy Seleucus, so implicitly that when it was discovered that Mettius Pompusianus, an ambitious Roman, had been putting it about that he was destined to be Emperor, Vespasian actually had him appointed to the consulate, so sure was he that his own astrologers were right when they said that Mettius had been wrongly advised.

Balbillus may have died at about the same time as Vespasian; had he survived there is no reason why the new Emperor, Vespasian's son Titus, could not have retained him, but his name vanished from record. Titus reigned for only two years, and in 81 was succeeded by his younger brother Domitian, who himself was so convinced by an astrologer's prediction that he would die by iron that he refused the senate's offer of a guard of honour to escort him with spears. For safety's sake, he appears to have believed all astrological predictions on principle. He executed Mettius Pompusianus, believing the prophesy that he would one day be Emperor, and Suetonius says that 'he had not failed to take careful note of the days and hours when the foremost men had been born, and as a result was destroying in advance not a few who did not feel the least hope of gaining power.' At least two astrologers seem to have predicted the hour of Domitian's death, and Suetonius says that as the stated hour approached the Emperor became more and more nervous. On 17 September 96, he told his servants to set aside some truffles for him until next day - in case he was around to eat them, for his death had been foretold for the 18th, when 'the Moon in Aquarius will be stained with blood'. He summoned the astrologer Ascletarius-Asclation and asked him if he could foresee his own death. The astrologer replied that he would be torn to pieces by dogs. Domitian had him executed immediately; but as the body was awaiting cremation, a sudden rainstorm put out the fire, the undertaker took shelter, and a pack of dogs destroyed the corpse. Early next morning the second astrologer, Larginus Proculus, was brought before Domitian in chains. Domitian ordered his execution, too, but following Caligula's example postponed this for twenty-four hours, in order that Larginus should see how wrong he had been.

It was at the fifth hour that the two astrologers had said Domitian would die. Nervously, Domitian again and again sent to know the time. Finally his bored servants assured him that the hour had passed, and the Emperor; much relieved, decided to bathe. A conspirator, Stephanus, asked if he could read to him for a while in the bath. Domitian agreed. Whereupon Stephanus produced a dagger and stabbed him, a number of other conspirators rushing in to join the execution.