The supplicia canum ("punishment of the dogs") was an annual sacrifice of ancient Roman religion in which live dogs were suspended from a furca ("fork") or cross (crux) and paraded. It appears on none of the extant Roman calendars, but a late source places it on August 3 (III Non. Aug.).
In the same procession, geese were decorated in gold and purple and carried in honor. Ancient sources who explain the origin of the supplicia say that the geese were honored for saving the city during the Gallic siege of Rome. When the Gauls launched a nocturnal assault by stealth on the citadel, the geese raised a noisy alarm. The failure of the watch dogs to bark was thereafter ritually punished each year.
Form of punishment
The implement on which the dog was carried is called a furca by Pliny (1st century AD), who describes it as made of elder wood, and a crux by Servius (4th century). Plutarch uses a verbal form referring to a stauros, "stake". After crucifixion was banned by Constantine I, the first emperor to convert to Christianity, the furca replaced the crux in sentencing prescribed by the legal code. The furca had a Y shape. The furca or palus ("stake") was a traditional instrument of punishment to which the condemned was bound for the supplicium de more maiorum ("punishment according to ancestral custom"), a form of capital punishment by scourging. His hands were tied, and his head was veiled. The stake was originally a dead or barren tree, possibly a fruit tree, or an arbor infelix ("unproductive tree" or "tree of ill fortune"), one of the several species regarded as under the guardianship (tutela) of the gods below (di inferi). The arbores infelices included trees and shrubs bearing black berries or fruit, as does the elder.
The punishment de more maiorum was distinct from crucifixion, which was reserved for slaves in the Republican era. Scourging at the stake was a sentence for treason (perduellio) and for committing a sex crime (stuprum) against or with one of the Vestals, who were the only women subject to this punishment. It lapsed into disuse during the late Republic of the 2nd and 1st centuries BC, but was revived during the Imperial period, when people of higher social status were exempt from it.
Binding and striking probably had a religious dimension, present also in other Roman rituals such as the Lupercalia, when youths clad in goatskins ran through the streets flailing bystanders with leather thongs from sacrificed goats and dogs, and the Mamuralia, for which a scapegoat figure was beaten with sticks. Although the dogs are not said to have been beaten, the supplicia canum shares some elements with the traditional punishment at the stake, and with the punishment Tiberius administered in the province of Africa to priests of the Carthaginian god identified with the Roman Saturn, usually regarded as Baal. In retribution for their ancestral custom of child sacrifice (whether or not such sacrifices actually occurred), Tiberius had them crucified on trees in their own temple precinct as offerings.
Ritual topography
The procession route involved the temples of Juventas ("Youth") and Summanus, an obscure and complex chthonic god of archaic Roman religion who shares some attributes with both Jupiter and Pluto. It may have taken place in the Circus Maximus.
Myth of origin
Sources mentioning the ritual agree that the "punishment" was inflicted on the dogs for their failure to warn the Romans of the stealth attack against the citadel by the Gauls during the Gallic siege of Rome in 390 BC (or 387). Legends vary regarding this historical event—the only sack of the city during the Republican era—but in the sources that allude to the supplicia canum, temple geese are said to have raised the alarm instead. Plutarch and Aelian rationalize the dogs' failure by explaining that the Gauls fed the siege-starved dogs and silenced them, while the geese called out excitedly. In recognition of this service, for the supplicia procession geese were decked out in purple and gold, then carried on a litter. The August 3 date, however, is hard to account for within the traditional chronology that had the Gauls setting fire to the city on July 19 and maintaining a siege through February.