Petronius Maximus, born around 397, was a wealthy senator and prominent aristocrat who briefly held the title of Roman emperor of the West in 455. During his short reign, Maximus orchestrated the murders of Aëtius, the Western Roman magister militum, and Valentinian III, the Western Roman emperor, solidifying his claim to power.
Maximus seized the throne the day after Valentinian’s death by garnering support from the Senate and bribing palace officials. To strengthen his position, he forced Valentinian’s widow to marry him and arranged a marriage between Valentinian’s daughter and his own son. He also canceled the engagement of his new wife’s daughter to the son of the Vandal king Genseric. This decision enraged his stepdaughter and Genseric, leading to the Vandal fleet sailing towards Rome. Unable to obtain assistance from the Visigoths, Maximus fled as the Vandals arrived, becoming separated from his retinue and bodyguards during the chaos and ultimately meeting his death. The Vandals proceeded to sack Rome entirely.
In his early career, Petronius Maximus achieved notable positions and honors. He held offices such as praetor, tribunus et notarius, comes sacrarum largitionum (count of the sacred largess), and praefectus urbi of Rome. As praefectus, he undertook the restoration of the Old St. Peter’s Basilica. Maximus also served as praetorian prefect, consul, and held the prestigious title of patrician. During his time as praetorian prefect of Italy, he constructed the Forum Petronii Maximi on the Caelian Hill in Rome.
The murder of Valentinian III and Maximus’s rise to power followed a complex series of events. Maximus allegedly poisoned Valentinian’s mind against Aëtius, resulting in Valentinian personally assassinating the magister militum. With Aëtius eliminated, Maximus allied himself with the eunuch Heraclius, a longtime opponent of Aëtius, to exert more influence over Valentinian. They convinced Valentinian that Aëtius planned to kill him, leading Valentinian to murder Aëtius during a meeting. Maximus then attempted to gain Aëtius’s former position but was denied by Valentinian. Frustrated, Maximus conspired to have Valentinian assassinated. With the help of two Scythian soldiers, Optilia and Thraustila, who believed they were avenging Aëtius, Maximus orchestrated the murder of Valentinian in March 455.
Maximus’s reign as emperor began with controversy, as his accession was not recognized by the Eastern Roman court in Constantinople. To strengthen his hold on power, he married Licinia Eudoxia, Valentinian’s widow, despite her suspicions of his involvement in her late husband’s assassination. Maximus favored Valentinian’s assassins and appointed Avitus as magister militum, sending him to gain support from the Visigoths in Toulouse. He also annulled the betrothal of Licinia’s daughter to the son of the Vandal king, provoking the Vandals to prepare an invasion of Italy.
Within two months of becoming emperor, Maximus received news of Geiseric’s impending arrival in Italy with the Vandal fleet. Recognizing the futility of mounting a defense without the expected Visigothic aid, Maximus decided to flee Rome and urged the Senate to join him. However, in the ensuing panic, Maximus was abandoned by his bodyguard and entourage, leaving him to fend for himself. On May 31, 455, Maximus rode out of the city alone and was attacked by an angry mob, resulting in his stoning to death. Some accounts attribute his death to a Roman soldier named Ursus. Maximus’s body was mutilated and thrown into the Tiber, marking the end of his 75-day reign. His son Palladius, who held the title of caesar and had married his stepsister Eudocia, likely faced execution.
Three days after Maximus’s death, on June 2, 455, Geiseric and the Vandals captured Rome, subjecting the city to looting and pillaging for two weeks. While the Vandals refrained from arson, torture, and murder due to Pope Leo I’s pleas, they destroyed temples, public buildings, private houses, and the emperor’s palace. The Vandals also took Licinia Eudoxia and her daughters as captives, along with numerous Romans who were transported as slaves to North Africa. This sack of Rome gave rise to the term “vandalism” to describe wanton destruction.