Roman Emperor Petronius Maximus: Life and Reign
Petronius Maximus was a Roman senator who briefly ruled as Western Roman Emperor in 455. He played a key role in the assassinations of Aetius and Valentinian III but was unable to maintain his rule.
Coinage of Petronius Maximus
Early Career & Contributions to Rome
Born around 397, Petronius Maximus belonged to the Roman aristocracy, with possible connections to the Anicius and Petronius families. He had an impressive political career, holding various high-ranking offices before becoming emperor. His earliest known position was that of praetor around 411, a role that marked the beginning of his rise within the imperial administration. Around 415, he served as a tribunus et notarius, an entry-level position in the imperial bureaucracy, before becoming comes sacrarum largitionum, responsible for managing the state treasury between 416 and 419.
Maximus further distinguished himself by serving as the urban prefect of Rome from 420 to 421 and again sometime before 439. His administrative capabilities earned him the position of praetorian prefect between 421 and 439, one of the most powerful non-imperial positions in the empire. In 433, he was appointed consul, the highest honor in the Roman state. His influence continued to grow as he was named praetorian prefect of Italy from 439 to 441, serving as the chief administrator and judge for the Western Empire. He was also granted a second consulship in 443 and received the prestigious title of patrician in 445, reinforcing his status as a key political figure in Rome.
His contributions to Rome included the construction of the Forum Petronii Maximi, a public space on the Caelian Hill, and the restoration of St. Peter’s Basilica. These projects demonstrated his commitment to civic development and his desire to leave a lasting mark on the city.
Petronius Maximus’s brief and chaotic rule epitomized the political instability of the late Western Roman Empire.
Murder of Valentinian III and Accession
Bust of Valentinian III at the Louvre in France.
Petronius Maximus played a pivotal role in the assassination of Emperor Valentinian III, orchestrating a series of events that led to his own rise to power. The sequence of events began when Maximus lost a wager to Valentinian and left his ring as collateral. The emperor used this opportunity to summon Maximus’s wife, Lucina, whom he had long desired. She, believing she had been called by her husband, arrived at the palace, only to be assaulted by the emperor. Furious and humiliated, Maximus sought revenge against Valentinian, but his motivations were also fueled by political ambition.
Maximus conspired with Heraclius, the eunuch chamberlain of Valentinian, who also sought to remove Aetius, the empire’s powerful general. They convinced Valentinian that Aetius was planning a coup, leading the emperor to personally kill Aetius in 454. However, once Aetius was eliminated, Maximus’s ambitions were still unfulfilled. When Valentinian refused to grant him the position of magister militum, Maximus took further action.
On March 16, 455, Maximus arranged for Valentinian III’s assassination. He enlisted the help of two former soldiers of Aetius, Optilas and Thraustilas, who resented Valentinian for killing their former commander. As Valentinian practiced archery in the Campus Martius, Optilas struck him in the head, followed by a fatal blow to his chest. Thraustilas killed Heraclius at the same time. Valentinian’s assassination left the Western Roman Empire without an obvious successor, and Maximus moved quickly to seize power.
Rise to Power and Policies
On March 17, 455, Maximus declared himself emperor, securing the support of the Senate and bribing palace officials. He married Valentinian’s widow, Licinia Eudoxia, to legitimize his claim, though she resented him and suspected his involvement in her husband’s murder. He also forced her daughter, Eudocia, to marry his son Palladius, breaking her betrothal to Huneric, the son of the Vandal king Geiseric.
Maximus sought to solidify his rule by appointing Avitus as magister militum and sending him to Toulouse to gain Visigothic support. However, his reign was met with resistance, and his legitimacy was questioned by the Eastern Roman Empire, which refused to recognize him as emperor.
Relief Possibly Depicting Aetius, Though Also Attributed to Stilicho (d. 408 AD), Dating Between 387–390 AD.
Fall and Death
Maximus’s decision to annul Eudocia’s betrothal to Huneric enraged Geiseric, who used it as a pretext to launch an invasion of Italy. By May 455, news reached Rome that a Vandal fleet was approaching. Panic spread throughout the city, and many citizens fled. Realizing that he had little support and that Avitus had not returned with Visigothic reinforcements, Maximus decided to abandon Rome.
On May 31, 455, as Maximus attempted to escape the city, he was confronted by an angry mob. Without his bodyguard or retinue to protect him, he was attacked and killed, either stoned by the crowd or slain by a Roman soldier named Ursus. His mutilated body was thrown into the Tiber. His son Palladius, who had briefly held the title of caesar, was likely executed as well.
His reliance on bribery and forced marriages to secure power, rather than military or administrative competence, made his rule unsustainable. His assassination by his own people underscored the fragile nature of Roman authority during this period.
Aftermath and the Sack of Rome
Three days after Maximus’s death, the Vandals entered Rome on June 2, 455. Over the course of two weeks, they thoroughly sacked the city, looting its treasures and taking many Romans as slaves. While Pope Leo I managed to persuade Geiseric to spare the city from destruction and unnecessary bloodshed, the Vandals plundered public buildings, temples, and private homes. Among the captives taken to North Africa were Empress Licinia Eudoxia and her daughters Placidia and Eudocia.
The sack of Rome in 455 was a major event that further demonstrated the weakness of the Western Roman Empire. The term “vandalism” originates from the destructive acts carried out during this invasion. The empire, already struggling with internal decay and external threats, never recovered from the loss of its capital’s wealth and prestige. The death of Maximus and the subsequent Vandal invasion set the stage for the final collapse of the Western Roman Empire, which fell in 476 with the deposition of Romulus Augustulus.
Frequently Asked Questions
How did Petronius Maximus come to power?
After orchestrating the murder of Valentinian III, he bribed palace officials and secured Senate support to be proclaimed emperor on March 17, 455.
The base of a statue bearing Petronius Maximus’ name.
What role did Valentinian III’s widow play in Maximus’s rule?
Maximus forced Licinia Eudoxia, Valentinian’s widow, to marry him. Suspecting his involvement in her husband’s murder, she secretly appealed to the Vandal king Geiseric for help.
Why did the Vandals attack Rome during Maximus’s reign?
Maximus broke the engagement between Valentinian’s daughter, Eudocia, and Huneric, son of Vandal king Geiseric, angering the Vandals and prompting their invasion.
How did Maximus respond to the Vandal threat?
He failed to secure military aid from the Visigoths and attempted to flee Rome as the Vandals approached, abandoning any defense efforts.
How did Petronius Maximus die?
As he fled Rome on May 31, 455, he was killed by an angry mob, possibly stoned to death or slain by a Roman soldier. His body was mutilated and thrown into the Tiber.
Historians view Maximus as an opportunist who lacked the military strength and political acumen necessary to govern effectively.
What happened to his family?
His son Palladius, who had briefly held the title of caesar, was likely executed after Maximus’s death.
What was the significance of the Vandal sack of Rome?
Three days after Maximus’s death, the Vandals sacked Rome for two weeks, plundering the city and taking Licinia Eudoxia and her daughters captive.
What was Petronius Maximus’s legacy?
His short and disastrous reign highlighted the instability of the Western Roman Empire, accelerating its decline and demonstrating its vulnerability to external threats.
