Such views, very much fringe ideas today, were widely held in the ancient world. The physiognomists taught that outward appearances were a sure key to character, and that that how individuals looked and how they behaved were inexorably linked.
While the theory goes back to at least the Babylonians, it was the Greeks who formalised it into a supposed science. The term Physiognomia appears first in a fifth century BC medical treatise associated with the famous physician Hippocrates, but the topic does not seems to have been treated extensively until the publication of the Physiognomica. This is often attributed to Aristotle but was almost certainly written a generation or so after his death, in about 300 BC. It provides detailed categories of various human features and their significance, arguing, for instance, that soft hair was a sign of cowardice, coarse hair of courage.
The physiognomists were highly influential. Ancient writers were very much inclined to present history in highly moral terms, and saw tyrants in particular as conforming to a narrow range of stereotypes. They were hence very receptive to physiognomical thinking. Suetonius may well have been swayed by them in his description of the fearsome appearance of Caligula, the epitome of arbitrary cruelty and immoral excesses; so too might Caligula’s contemporary, the philosopher Seneca, who described the Emperor as physically repellent, and insisted that his expression was so fiendish that it was a form of torture.
A Roman marble portrait of the Emperor Gaius, known as Caligula (37-41 AD). This work is offered in our Antiquities Sale in London on 15 April. Estimate: £60,000-80,000
Rest assured that we do not need to take Suetonius and Seneca too seriously here. When in A.D. 37 Caligula first made his way to Rome on the death of his predecessor, Tiberius, he received a rapturous reception from an adoring populace, something unthinkable had his appearance excited either ridicule or revulsion. Moreover, official Roman coinage generally portrayed Emperors as they really were and the portraits on Caligula’s coins are reassuringly unremarkable. These perfectly ‘normal’ likenesses are reflected also in his sculpture.
Coin-engravers and sculptors were clearly happy to ignore the physiognomists to produce what were probably quite life-like images. But Caligula’s fearsome reputation did indeed have a significant, if indirect, impact on his statues. In Rome his effigies were vandalised while he was alive, and placed under armed guards. These proved ineffective in the confusion following his assassination in January, A.D. 41, when some of the statues seem to have been toppled, and his successor Claudius discreetly arranged for the remaining ones to be removed (there seems to have been a similar scheme, not seriously implemented, to melt down coins bearing his image).
Marble bust of Roman Emperor Gaius Julius Caesar Augustus Germanicus (12-41), known as Caligula, in circa 23 A.D. Venice, Museo Archeologico Nazionale; De Agostini Picture Library / A. Dagli Orti. Copyright: www.bridgemanart.com
Surviving sculptures of Caligula are consequently very rare: fewer than 50 are known, almost certainly a very tiny fraction of those originally sculpted. Moreover the memory of his abominable conduct impacted those that do survive. One economical approach to dealing with expensive marble statues no longer fit for public display was to recycle them into the images of other, more acceptable, members of the elite. This happened fairly extensively in the case of Caligula, and indeed he is the first known figure to have his portraits, in fact about half of those that have been identified, reworked on a large scale, the majority into representations of Claudius.
Ironically, a handful of statues actually benefitted from the depth of public loathing. Occasionally it seems that the order to remove them from public view was taken literally, and to judge from their excellent condition it seems that some of his heads were permanently stored away or perhaps even buried. It is in fact highly unlikely that any Caligulan image was left in public view, to be exposed to the elements and to suffer time's normal wear and tear.
When a Caligulan head shows signs of serious damage, this is almost certainly the consequence of deliberate contemporary mutilation after his death. Some likenesses of this abominated figure show clear signs of defacement by a hammer or a chisel before they could be safely stored, or, in some cases, reworked. Such damage is an integral part of the sculpture's history, a silent witness to the violence of the times.
Anthony A. Barrett is professor of classics at the University of British Columbia in Vancouver and the author of Caligula: The Abuse of Power (Routledge, 2015)
For more features, interviews and videos, see our Art Digest homepage