chapter  5
22 Pages

Signs of strain

The illness that laid Caligula low in the latter part of AD 37 was clearly a very serious one. The popular reaction to reports of it, both in Rome and throughout the empire, bordered on the manic.1 Crowds slept in the open outside the imperial residence, waiting for bulletins. The equestrian Atanius Secundus announced that he would fight as a gladiator, and a Publius Afranius Potitus even vowed publicly to give his own life, should the emperor be spared; extravagant offers, although with precedents in similar vows for Augustus’ recovery, when, at the time of the settlement in 27 BC, a Sextus Pacuvius vowed his life for the well-being of Augustus, and tried to persuaded onlookers to do the same.2 Philo suggests that the illness was the consequence of some kind of nervous breakdown, brought on by the stress of the first six months of the reign, and some modern scholars broadly agree with him.3 Others have sought a more specifically physical ailment. Among recent diagnoses, it has been proposed that Caligula may have suffered from epidemic encephalitis, which leads to symptoms of mental derangement. Another suggestion is hyperthyroidism, which can be triggered by serious stress. The strain of rule could have caused Caligula’s thyroid gland to become overactive, thus contributing to his breakdown. But the kind of hyperthyroidism that is triggered by stress is almost invariably a chronic condition and does not disappear after a few months.4 Or the illness may have been a viral one that affected the central nervous system, with residual mental symptoms.5 All these, and other, speculations about the nature of the illness are in the end unprovable, and, like speculations about Caligula’s mental competence, rely on descriptions of symptoms that may not have been well understood at the time and have since been much distorted by the process of source transmission. Nor can we be sure that the illness had any long-term effect. The sources seem to see it as a turning point in Caligula’s reign, and Philo implies a causative link between it and his subsequent behaviour. But it can at best have had only a minor direct influence on the course of events, since there is no evidence of any dramatic change in Caligula’s behaviour in 37, and his serious excesses and clashes with the senate do not begin until 39.6

The precise date of the illness is also uncertain. Philo provides the information that it fell in the eighth month of his reign (mid-October to mid-November) and

that word of it was brought by sailors as they returned to their home ports at the end of the sailing season, traditionally placed at November 11.7 If the illness occurred this late it would be difficult to fit Caligula’s recovery, and other events recorded for late 37, into the short time remaining in the year. Also, Dio implies that he fell ill not long after his first consulship, which he held up to the end of August. It could very well be that he was struck down very shortly after being acclaimed pater patriae, on September 21; for the first week or thereabouts little heed would likely be taken of his indisposition, but when the illness showed no sign of abating the alarm would have grown, and the reverberations of that alarm could have reached Alexandria in mid-October. Then his progress through gradual improvement to final recovery would continue to be brought by sailors right up to the end of the shipping season. There is possibly a clue in the calendar of Egypt. One of the honorific months introduced there by Caligula (it did not survive him) was Soter (‘Saviour’). This is known to have been the equivalent of the Egyptian Phaophi, which began on September 28 and lasted until October 27.8 Soter might well have been named because during this month he began his initial recovery, and that initial recovery might, accordingly, be placed in late October.9