Caligula delayed his official entry into Rome until the celebration of his ovation on his birthday. He had been in the vicinity of Rome since the end of May but refrained from entering the city, perhaps out of fear of a conspiracy. The official cult of his genius might have been a way to protect himself against perceived threats from the nobility. He appealed to the people by carrying out a congiarium showing gold and silver from the roof of the palace for several days. Unfortunately, many people were trampled to death and injured in the rush to take the money. Dio says the emperor tossed bits of iron mixed with the coins (59.25.5; AJ 19.71; Cal. 37.1).

The conspiracy that led to Caligula’s assassination is better documented than those of Macro/Gemellus and Gaetulicus/Lepidus but much about it remains obscure. The group of conspirators consisted of many people drawn into the plot for various reasons. In a large conspiracy many sub-groups are likely to exist from the core conspirators and could act independently from their own motives. A group of conspirators could be exposed without endangering the central organizers. Ancient sources are vague on the number of conspiracies operating in the last six months of Caligula’s reign. Suetonius says there were one or two other plots involving the prefects of the guard and imperial freedmen (Cal. 56.1). Josephus, vaguer still, says conspiracies were commonly formed against the emperor (AJ 19.14). Dio and Josephus say the final plot was widely known but Tacitus contradicts them by saying it was kept a secret, the very reason it succeeded. Both views are probably correct. Caligula managed to catch several people involved in the plot but missed the key conspirators (AJ 19.60-2; Hist. 3.68.1; Dio 59.29.1).

Fear of conspiracies during the last months of his life may be responsible for accounts of his ruthless behavior. Seneca, in particular, provides descriptions of his brutality, much of it directed toward senators, as presumed conspirators were scourged to death, tortured by fire and the rack and others beheaded. Caligula was said to be so impatient he had his victim executed during the night, rather than wait for dawn. We have few details from ancient sources, let alone any names. One of the better known stories adds the refinement of having a father watch his son’s execution. Similar stories were circulated about Augustus (On Anger 3.18.3-19; Aug. 13.2, Cal. 27.4). Such oft-repeated stories make it difficult to prove or disprove those told for Caligula. One such story involves a man named Pastor, who is otherwise unknown. His son was executed allegedly for his foppish manners. Pastor begged for his son’s life but Caligula forced him to watch the execution on the spot, then invited Pastor to a banquet that night. During dinner, the emperor drank to Pastor’s health watching to make sure his reluctant guest drank his wine. Pastor went along with the performance because he had another son (On Anger 2.33.3-7). [1]

A confusing story is that of Sextus Papinius. Dio says that Papinius and his father, Anicius Cerialis, were discovered to be part of a conspiracy and were tortured. Cerialis held his tongue but Papinius was induced to speak after promised a pardon. After giving his information, Cerialis and others were executed in front of Papinius (59.25.5b). Seneca contradicts Dio in relating that Papinius was tortured to death for Caligula’s amusement, saying nothing about a confession (On Anger 3.18.3). The role of Cerialis is further questioned by Tacitus, who notes that he was forced to commit suicide in 66 because of disloyalty to Nero. Cerialis’ death caused little concern since he had betrayed a conspiracy to Caligula (Ann. 16.17).

The last story involves Betilienus Bassus and his father, the procurator Betilienus Capito. Seneca and Dio imply that their deaths coincided with the betrayal of Cerialis, but Dio alone adds that Capito was forced to watch the execution of his son and closed his eyes. Caligula ordered Capito to be killed as well and the procurator tried to save himself by naming other conspirators that included the prefects of the guards and Callistus. When he added Caesonia’s name he was not taken seriously (On Anger 3.18.3; Dio 59.25.6-7).

One of the conspirators was Julius Canus, a Stoic philosopher – the first instance of a philosopher opposed to a ruler (Tranq. 14.4-10). Although the Stoics were reconciled to the idea of an enlightened monarch their opposition to the principate grew under Nero and later caused Vespasian and Domitian to banish philosophers from Rome. According to Seneca, Canus had argued with Caligula and gotten the better of the emperor. As he left, Caligula warned the philosopher not to be too proud of himself, as if he had ordered his execution. Canus replied with, "Thank you, excellent prince." Seneca implies that the death penalty was given to Canus at the whim of Caligula. However, ten days elapsed between his sentence and execution - the statutory period in Senate trials. It is likely that Canus was tried and convicted before the Senate and not by Caligula (Sen. Ep. 73.1, 103.5, Tranq. 14.4-6). Another senator who was executed was Julius Graecinus, father of Agricola. He, too, was a philosopher and may have been a member of the embryonic Stoic Opposition. Tacitus says he was executed because he refused to prosecute Silanus, but that event had occurred two years earlier (Agr. 4.1; Sen. Ep. 29.6, Ben. 2.21.5). Perhaps Graecinus remained a threat in Caligula’s eyes and when he became implicated in a conspiracy his fate was sealed.

An impressive story of heroism concerned Pomponius, a man of consular rank with leanings toward Epicurean beliefs. His involvement in the conspiracy was betrayed by Timidius, and the chief witness was his mistress Quintilia, a beautiful actress (Sen. Ben. 2.12.1; AJ 19.32-36; Cal. 16.4; Dio 59.26.4). She was subjected to horrifying tortures that left her beauty ruined and body broken, but she revealed nothing of the conspiracy. Significantly, Quintila exchanged a secret signal with Cassius Chaera, who was in charge of the interrogation, that was meant to reassure him. Caligula was so moved by her courage and shattered beauty that he gave her money by way of compensation, put at 800,000 sesterces by Suetonius. Pomponius was not nearly as brave and kissed Caligula’s foot when he was acquitted.

Caligula did manage to uncover one senatorial conspirator: Scribonius Proculus. The emperor cleverly isolated him by granting the senator amnesty during a meeting of the Senate when he also announced that there were only a few senators with whom he was angry. This was a signal to those members who were eager to prove their loyalty to ferret out those opposed to Caligula. Caligula’s freedman, Protogenes, carried two books with him called Gladius (sword) and Pugio (dagger) that contained the names of those whom Caligula had marked for execution. Shortly after Proculus had been granted amnesty, the freedman entered the Senate, and was greeted by individual senators. When Proculus did so, Protogenes rebuked him. This was a signal for other senators, willing to act as Caligula’s tool, who proceeded to hack him to death (Cal. 28; Dio 59.26.1-2). Protogenes was later executed by Claudius who also had the books destroyed (Dio 60.4.5). The death of Proculus was a setback for senators prepared to stand up to Caligula and many more members rushed to ingratiate themselves with the emperor.

The most critical development in the conspiracy was the support of members of Caligula’s own household. Callistus was implicated by Josephus, and Tacitus said he had a major role in Caligula’s death. He was highly influential and wealthy, and vulnerable should Caligula fall from power. Josephus says he paid court to Claudius in anticipation of the emperor’s assassination and Suetonius adds that Callistus found allies among other freedmen. Callistus made a successful transition to Claudius’ reign where he became a libellis (AJ 19.64-69; Ann. 11.29.1, 12.1.3; Cal. 56.1; Dio 59.29.1).

Assassination

Caligula’s final weeks are the best documented of his life. Josephus provides the majority of the information but his account is confused from a corrupted text. Military men, chief among them being Cassius Chaerea, a tribune of the Praetorian Guard, carried out the assassination. Until the murder, Chaerea was most famous for his action during the mutiny of 14 when he cut a path through a group of mutineers (Ann. 1.32.5). For Josephus, Chaerea is a noble idealist motivated by Republican liberties and is the inspiration and organizer of the conspiracy as well as the agent of the murder. All of the sources agree that Chaerea had a grudge against Caligula, for although manly in bearing he had a weak, high-pitched voice that sounded effemenent. He was the butt of jokes by Caligula, whom he called his "lass" (De Caes. 4.4). Dio says that when Chaerea asked for the daily watchword, Caligula chose suggestive expressions like "Venus" or "Priapus" causing his fellow Praetorians no end of laughter. On those occasions when Chaerea had to thank the emperor, Caligula extended his hand to be kissed, then made an obscene gesture. Perhaps another reason for Caligula’s scrutiny was poor performance of his duties. Chaerea was a tax collector for the imperial treasury but was lax in collecting taxes. Josephus claims, unconvincingly, that he felt pity for the debtors (Sen. On Firmness 18.3; AJ 19.20.21; Cal. 56.2; Dio 59.29.2). Chaerea had the support of two other tribunes of the guard: Papinius, who is otherwise unknown, and Cornelius Sabinus (AJ 19.46; Cal. 58.2; Dio 59.29.1).

Behind Chaerea was Annius Vinicianus who, according to Josephus (whose text mistakenly refers to him as Minicianus), was motivated to join the conspiracy out of his friendship for Lepidus, and because he was a potential target of Caligula (AJ 19.20, 49, 52; Dio 60.15.1). Josephus implausibly suggests that Chaerea and Sabinus approached Vinicianus to join their conspiracy, and the senator meekly followed their lead. More probably, Vinicianus was at the heart of the conspiracy and was motivated not by a return to the Republic but engineering a coup. [2]  Another senator who had a major role was Valerius Asiaticus. Seneca describes him as a friend of Caligula and devoted to Antonia. However, there was a falling out between the emperor and senator. We hear that Caligula would taunt Asiaticus at public banquets over his wife’s lack of prowess in bed. When Caligula was assassinated, Asiaticus responded to the furious demands of the people for the identity of the assassins saying he wished it was he (On Firmness 18.2; AJ 19.159; Ann. 11.1-3). Two senators involved in the plot were to loose their lives during the murder. One was Publius Nonius Asprenas, who was cut down by the guards; the other was Lucius Norbanus Balbus. Nothing further is known about them (Dio 59.9.1; AJ 19.123).

Josephus says that Chaerea was anxious to do the murder and had to be restrained. The conspirators argued when to carry out the assassination and settled on the Palatine Games that began on January 17, 41. For these games, dedicated to Augustus, a temporary wooden theater was constructed in front of the imperial residence; it was a confining space that would be crowded with thousands of spectators. Caligula’s German bodyguard, notable for their strength and brutality, would be hampered in coming to his rescue. Another consideration was that the emperor was to depart for Alexandria following the games, even though the weather would be against the journey. Philo claimed that Caligula planned to travel along the coast and dock every day (AJ 19.80-83; Leg. 250, 338).

There were many portents of Caligula’s assassination. Perhaps the most significant is the dream Caligula had where he was standing next to the throne of Jupiter, when the god literally kicked him out of heaven with the toe of his right foot. The day selected for the deed was propitious for the plays being performed. One was a farce by Catullus called The Laureolus, in which the main character falls during an escape and vomits blood. The dancer Mnester was presenting the Cinyras, in which the hero and his daughter are slain. Suetonius noted that the same play had been performed during the games when Philip of Macedon was assassinated (AJ 19.9.4-5; Cal. 57.4). Josephus incorrectly identified the same day, January 24, as the date of Philip’s murder.

Caligula entered the wooden theater in the morning when it was already crowded. He was in high spirits. No seating had been set aside for the spectators, so the emperor was amused to see senators jostling with freedmen to find a seat. The day had begun with a sacrifice of a flamingo to Divus Augustus. When the bird was struck, it’s blood spurted out on either the toga of Caligula or Publius Nonius Asprenas, depending on the source (on Asprenas AJ 19.87; on Caligula Cal. 57.4). Following the sacrifice, the emperor took his seat, eating and drinking with his companions. Fruit had been distributed among the spectators which attracted some exotic birds that afforded entertainment as people tried to catch them (AJ 19.86, 93; Dio 59.29.5). Attending the games that day was Cluvius Rufus, who is thought to have been the historian of the same name. He had an exchange with an unidentified ex-consul and was asked if he had heard of the planned coup. This led Cluvius to admonish his friend quoting Homer (misquoted by Josephus) "Be silent, sir, lest some other of the Achaens hear the report" (AJ 19.91-92). If true, this conversation indicates the widespread knowledge of the conspiracy.

Caligula was in the habit of leaving the games at midday to bathe and have lunch before returning. The conspirators planned their attack to take place in one of the narrow passageways that led from the theater to the palace. But Caligula showed no sign of wanting to leave, perhaps because it was the last day of the games or stomach troubles from the night before. Vinicianus, feeling that the opportunity was slipping away, left his seat to urge Chaerea to "be bold." However, as he was leaving, Caligula tugged on his toga asking in a friendly way where he was going. The senator had no choice but to return to his seat.

Caligula was at last persuaded to leave the theater by Asprenas (AJ 19.98). Suetonius says this occurred at the seventh hour; Josephus gives the ninth hour. His departure was just in time as Chaerea, thinking along the lines of Vinicianus, was about to abandon the plan and murder Caligula where he sat. As the imperial party left the theater, Caligula’s uncle Claudius, Marcus Vinicius and Valerius Asiaticus were in front. The crowd was held back ostensibly to show respect for the emperor but in reality to allow the conspirators to get close (AJ 19.96-103; Cal. 56.2, 58.1, Claud. 10.1). Caligula followed with a friend whose name is confused in Josephus’ manuscript but is usually reconstructed as Paulus Arruntis. At the last moment, the emperor decided (or was convinced) to take the shorter route to the baths than the one being taken by his retinue, which happened to be the only route that was unguarded. Once in the passageway, Caligula paused to inspect a group of performers who had come from the province of Asia (Dio says some of the youths were from Greece). Whether they were performing as part of the games or had come to sing a hymn to the emperor or participate in the Pyrrhic dances is unknown. Josephus says they were rehearsing in the passageway, an odd place it would seem unless they invited to wait for the emperor by one of the conspirators. Caligula spoke to one of the youths and was impressed enough to have an immediate performance which the leader was forced to decline as he had a chill (AJ 19.102-5; Cal. 58.1; Dio 59.29.6). This pause had given the conspirators time to position themselves, and when in place they struck.

The murder was carried out as if it were a ritual sacrifice. Josephus says Caligula was behaving in a typically mischievous fashion when Chaerea asked him for the watchword. Caligula gave his usual mocking reply whereupon he slashed the emperor between the neck and shoulders. This blow was not mortal and as Caligula turned in agony to make his escape Sabinus struck him. Then, a crowd of conspirators surrounded Caligula to finish him off. Suetonius knew of two accounts of the murder. One is close to Josephus and has Chaerea creeping up as Caligula was speaking to the youth. He stabbed Caligula in the neck calling out the ritual formula of sacrifice, hoc age (Do I strike now). Then, Sabinus stabbed him in the chest. The second account has Caligula giving the password Jupiter and Chaerea replying accipe ratum (receive as fulfilled), referring to Jupiter as the bringer of sudden death. The tribune drove his sword into Caligula’s jaw (Cal. 58.2-3). Following the initial blow, the conspirators joined in the murder, continuing to stab Caligula even after he was dead; some spat on him and some cheered the others on (Dio 59.29.7, 30.1; AJ 19.110).

The only agreement between the sources is that the first blow was not mortal. This was of little consequence since, by Suetonius’ count, the emperor was stabbed over thirty times. Josephus identifies the fatal blow struck by someone named Aquila, while Dio claims the assassins ate Caligula’s flesh, further pointing up the sacrificial nature of the murder (On Firmness 18.3; AJ 19.105-113; Cal. 58.2-3; Dio 59.29.7, 30.1). The only resistance offered the assassins came from Caligula’s litter-bearers, who fought with their litter poles – an example that Caligula could claim the loyalty of the humbler members of his household. With the passageway to the theater blocked by Caligula’s German bodyguard, the assassins took the passage to the palace finding refuge in the "House of Germanicus."

When Caligula’s bodyguard arrived on the scene they were so enraged they killed people indiscriminately. Most of the conspirators had fled but those who remained were cut down along with the innocent. The first killed was Asprenas. If his was the toga spattered with blood from the earlier sacrifice, he may have been thought a conspirator when he was not involved in the plot. However, there is no evidence to explain why he lingered so long near the body (AJ 19.123-6; Cal. 58.3; Dio 59.30.1b). Josephus says someone named Anteius was killed because he could not resist the pleasure of looking at Caligula’s corpse. Some of the conspirators owed their lives to a physician named Alcyon who had been summoned to treat some wounded men. The assassins were able to get past the Germans with the lie that they were fetching needed supplies for Alcyon (AJ 19.157). Vinicianus was seized by Praetorians apparently involved in the plot since he was brought before Clemens and released (AJ 19.153-6).

The Germans guarded the exits of the theater, looking for additional conspirators, while others entered the theater with the heads of their victims, which they placed on the altar. Josephus concedes that there was not universal joy that Caligula was dead. Many present in the theater were stunned, and rumors that Caligula was alive and being tended by a physician made many believe this was a test of loyalty. The Germans were brought to order probably because the anguish of the crowd was genuine. The situation was diffused when Arruntius Evarestus, an auctioneer by trade, entered the theater wearing mourning clothes and, with his powerful voice, announced that Caligula had been assassinated (AJ 145-147)

In the meantime, a tribune of the Guard named Julius Lupus murdered Caesonia and her daughter. We are told she was stretched out on the body of her husband, reproaching him for not believing her predictions, when she was killed (AJ 19.190-200; Cal. 59). Josephus goes on to say that her murder occurred during the evening of January 24, after the Senate had met in emergency session. It is hard to believe that Caesonia would not have sought safety and that the conspirators would have delayed her murder. The fate of the empress would have been a matter that the conspirators had to decide before they acted, and Lupus had been selected to perform the deed. The account of her draped over her husband’s body is fantasy.

Before evening fell, Agrippa arranged to have Caligula’s body taken to the Gardens of Lamii, imperial property on the Esquiline Hill, outside the limits of Rome. The body was given a hasty cremation and buried in a temporary grave under the sod. On their return from exile, Agrippina and Julia Livilla had the body exhumed and gave it a proper cremation and burial. The final location of Caligula’s remains is unknown but they were probably interred in the Mausoleum of Augustus. Even in death, so it seems, Caligula could not resist being mischievous. His ghost was said to haunt the Lamian Gardens until he received a proper burial, and his apparition also visited the part of the palace where he was murdered until it burned down, probably in the great fire of 80.

With the death of Caligula the Senate enjoyed a brief period of power, feeling that they would now have as important a role as they had enjoyed during the Republic. They were mistaken. Unknown to the senators, Claudius had been proclaimed emperor by the Praetorians. Talk about restoring the Republic was a reflection of the fashion among some senators. What opposition members wanted was to change a bad emperor with a good one. Their use of the word "liberty" had the meaning of an emperor who respected the traditions of the Senate, including the right of senators to speak their mind. (allen p. 17, swan 157-9) The Senate passed a decree charging Caligula with unspecified crimes and there were calls that a damnatio memoriae be leveled against all of the Caesars and the temples of the deified members of the family be destroyed. The consuls took the precaution of having funds transferred from the treasuries (Cal. 60; Dio 59.30.3, 60.1.1).

While the Senate congratulated itself, the people expressed their anger. There was a considerable amount of distress over Caligula’s murder and a lack of enthusiasm for a return to a Republican system that would restore the privileges of the nobility (AJ 19.228). A noisy, spontaneously organized, meeting took place in the forum with angry demands by the crowd to know the identity of the assassins (AJ 19.159-60; Ann. 11.1). While some senators toyed with the notion to do away with the principate, the people wanted some form of it to remain. The Praetorians, by contrast, had a coherent plan from the outset. Convinced that the principate needed to be retained, they had probably chosen Claudius as the new emperor prior to the assassination of Caligula. As the son of the legendary Nero Claudius Drusus and brother of Germanicus, Claudius enjoyed a prestige with the soldiers that no member of the senate could match. He probably had no direct involvement in his nephew’s murder and was kept informed by Callistus on the progress of the conspiracy. As the assassination took place, Claudius was in the guarded passageway that led to the palace. As events unfolded, Claudius took refuge in the palace where, like Vinicianus, he was "found" by a Praetorian (fittingly named Gratus (grateful)) who was loyal to Clemens. When Claudius was brought to the Praetorian camp for safety, the fate of the principate was decided.

1 - M.P. Chareslworth,"The Tradition About Caligula" CHJ 4(1933), 110-111.