Why Is Caligula’s Relationship with the Senate Controversial?

During his brief four-year reign, Caligula had a tumultuous relationship with the Roman Senate. While the emperor wielded immense power, the Senate won in the end, tarnishing the emperor’s name for posterity.

Oct 25, 2023By Vedran Bileta, MA in Late Antique, Byzantine, and Early Modern History, BA in History

caligula senate controversy


Caligula, one of the most infamous Roman emperors, is known for his controversial relationship with the Senate of Rome. The Senate welcomed the new emperor cordially, but the relationship swiftly deteriorated following Caligula’s near-mortal illness. Unlike his predecessors, Emperor Caligula wanted to rule as the absolute monarch, while the Senate wanted to restore the power lost with the establishment of the Roman Empire. The opposing ambitions led to inevitable conflict between the young and reckless emperor and the senatorial aristocracy. In the end, the Senate managed to eliminate Caligula, with the help of the Praetorian Guard, but failed to restore the Roman Republic. However, the senatorial aristocracy played a crucial role in tarnishing Emperor Caligula’s name for posterity, making an average autocrat an epic villain.


The Roman Senate Warmly Welcomed Emperor Caligula

numismatic portrait caligula roman emperor
Numismatic portrait of emperor Caligula, 40 CE. Source: The British Museum


Most of Caligula’s brief four-year-long reign was marked by a bitter struggle with the Roman Senate, eventually leading to the emperor’s violent demise. But at the very beginning, the senators warmly welcomed the new emperor. In fact, after Emperor Tiberius died in 37 CE, the Senate promptly acclaimed Caligula as the new imperator. This was a big deal, as there was no clear line of succession in the early years of the Roman Empire. The first emperor, Augustus, spent decades, searching for an heir, eventually deciding on Tiberius. But for the succession to be legitimized, the new emperor had to get approval from the Senate and the army, two pillars of the Roman imperial state. 


Caligula Initially Cooperated with the Senate

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Coin commemorating Caligula’s abolition of tax, 38 CE, private collection

For his part, Caligula has shown a willingness to cooperate with the Senate. Young, popular, and charismatic, the new emperor was a stark contrast to the old and paranoid Tiberius. Immediately after taking the purple, Caligula made a major speech to the Senate, where he denounced the unpopular actions of his predecessor and promised he would behave better. Those were not just the empty words. Caligula ended treason trials, freed political prisoners, and recalled those sent to exile by Tiberius, many of them senators. He also abolished high taxes and restored the practice of elections. 


The Emperor’s Relationship with the Senate Soon Deteriorated

caligula cuirass bust
Cuirass bust of emperor Caligula, 37-41 CE


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However, following his sudden illness, Caligula’s relationship with the Senate quickly degenerated, first into a stand-off and, before long, to an open conflict. The Roman Empire was still in its infancy, and the Senate still held considerable power. After all, both Augustus and Tiberius avoided displaying absolute power, playing the part of the “first citizen.” This was particularly case with Tiberius, who spent the last years of his reign secluded from the world on the island of Capri, leaving the governing to the Senate. Caligula, however, wanted more. An admirer of the Hellenistic East, the new emperor wanted to rule as an absolutist monarch. For the Senate, this was deeply troubling. A collision between the two was imminent. 


Caligula Enjoyed Mocking the Senators

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Statue of a youth on horseback (probably representing emperor Caligula), early 1st century CE. Source: The British Museum, London


During Caligula’s illness, the business in the Empire continued as usual. The Senate met and passed decrees, while governors (also senators) governed the provinces. Once he recovered, Caligula was determined to show the senators that he was in charge. Young and powerful, the emperor enjoyed mocking the older senators and humiliating them with various pranks. When the Senate denied Caligula’s triumph, the emperor ordered a pontoon bridge to be built near senatorial estates at Baiae. Once completed, the emperor crossed it with his troops and then engaged in drunken debauchery to annoy the resting senators. The most infamous tale – of Incitatus, Caligula’s favorite horse whom he did not name the consul – was a clear display of the imperial power and the senator’s impotence and uselessness.


The Paranoid Emperor Wanted to Get Rid of the Senate

praetorian guard
Relief depicting the Praetorian Guard (originally part of the Arch of Claudius), 51-52 CE. Source: Louvre-Lens Museum, France.


Following his recovery, Caligula grew more and more paranoid. The emperor ordered the execution of his potential rival, Tiberius’ grandson Gemellus. Aware of the fate of his namesake and ancestor, Julius Caesar, he reintroduced the purges and targeted the Roman Senate. Many senators lost their property. More than thirty lost their lives: executed or forced to commit suicide. Although the elites considered this an act of tyranny, this sort of violence was, in essence, a bloody struggle for political supremacy. The Senate retaliated – but the attempts on the emperor’s life failed, as Caligula enjoyed the protection of the army and, more importantly, the Praetorian Guard. 


Caligula Was the First Absolutist Monarch in Rome

Marble portrait bust of the emperor Gaius, known as Caligula, The Met
Marble portrait bust of Emperor Gaius, known as Caligula. Source: The Metropolitan Museum of Art, New York.


Caligula’s deep admiration of the Hellenistic East, considered by the Roman elites as autocratic and decadent, further deepened the rift with the Senate. Caligula’s attempts to emulate the rule of the Hellenistic god-kings led to many scandals, reported by historian Suetonius in vivid detail, later used as evidence of the emperor’s madness. The infamous story of the emperor’s incestual and public relationship with his three sisters is probably a rumor. But if true, it can be seen as an attempt to keep the royal bloodline pure, akin to the rulers of Ptolemaic Egypt. Similarly, the emperor’s declaration of his godhood could be a culmination of his oriental obsessions and growing paranoia. An attempt to become untouchable by assassinations he feared. And which ultimately backfired.


Emperor Caligula Lost His Battle with the Senate

alma tadema death emperor caligula
A Roman Emperor: 41 CE, by Sir Lawrence Alma-Tadema, 1871. Source: The Walters Art Museum, Baltimore


To fully remove the Senate’s influence, Caligula declared that he would leave Rome and move the capital to Alexandria. It was a step too far, as Egypt was a province to which the senators could enter only with the emperor’s permission. The Senate had no choice but to act. Caligula was protected by an elite bodyguard – the Praetorian Guard. However, the emperor was a stubborn and narcissistic boy, lacking diplomatic skills. When Caligula insulted one of the Praetorian officers, Cassius Chaerea, the senators got a valuable ally. On January 24, 41 CE, Emperor Caligula fell victim to a bloody palace coup.

The Senate’s plan to abolish the Roman Empire spectacularly failed after the Praetorian Guard installed Caligula’s uncle Claudius as the next emperor. Yet, the Senate had the final laugh. Senators like Suetonius were the ones who wrote history, and used their power to slander the reputation of the ill-fated rulers to justify their removal and legitimize later imperial dynasties, making Caligula, an arrogant and narcissistic boy, and average autocrat, a madman and an epic villain.

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By Vedran BiletaMA in Late Antique, Byzantine, and Early Modern History, BA in HistoryVedran is a doctoral researcher, based in Budapest. His main interest is Ancient History, in particular the Late Roman period. When not spending time with the military elites of the Late Roman West, he is sharing his passion for history with those willing to listen. In his free time, Vedran is wargaming and discussing Star Trek.