The Establishment of the Roman Republic

Learning Objective

  • Explain why and how Rome transitioned from a monarchy to a republic

Key Points

  • The Roman monarchy was overthrown around 509 BCE, during a political revolution that resulted in the expulsion of Lucius Tarquinius Superbus, the last king of Rome.
  • Despite waging a number of successful campaigns against Rome’s neighbors, securing Rome’s position as head of the Latin cities, and engaging in a series of public works, Tarquinius was a very unpopular king, due to his violence and abuses of power.
  • When word spread that Tarquinius’s son raped Lucretia, the wife of the governor of Collatia, an uprising occurred in which a number of prominent patricians argued for a change in government.
  • A general election was held during a legal assembly, and participants voted in favor of the establishment of a Roman republic.
  • Subsequently, all Tarquins were exiled from Rome and an interrex and two consuls were established to lead the new republic.



Literally, this translates to mean a ruler that presides over the period between the rule of two separate kings; or, in other words, a short-term regent.


A general body of free Roman citizens who were part of the lower strata of society.


A group of ruling class families in ancient Rome.

The Roman monarchy was overthrown around 509 BCE, during a political revolution that resulted in the expulsion of Lucius Tarquinius Superbus, the last king of Rome. Subsequently, the Roman Republic was established.


Tarquinius was the son of Lucius Tarquinius Priscus, the fifth king of Rome’s Seven Kings period. Tarquinius was married to Tullia Minor, the daughter of Servius Tullius, the sixth king of Rome’s Seven Kings period. Around 535 BCE, Tarquinius and his wife, Tullia Minor, arranged for the murder of his father-in-law. Tarquinius became king following Servius Tullius’s death.

Tarquinius waged a number of successful campaigns against Rome’s neighbors, including the Volsci, Gabii, and the Rutuli. He also secured Rome’s position as head of the Latin cities, and engaged in a series of public works, such as the completion of the Temple of Jupiter Optimus Maximus. However, Tarquinius remained an unpopular king for a number of reasons. He refused to bury his predecessor and executed a number of leading senators whom he suspected remained loyal to Servius. Following these actions, he refused to replace the senators he executed and refused to consult the Senate in matters of government going forward, thus diminishing the size and influence of the Senate greatly. He also went on to judge capital criminal cases without the advice of his counselors, stoking fear among his political opponents that they would be unfairly targeted.

The Rape of Lucretia and An Uprising


Tarquin and Lucretia. Titian’s Tarquin and Lucretia (1571).

During Tarquinius’s war with the Rutuli, his son, Sextus Tarquinius, was sent on a military errand to Collatia, where he was received with great hospitality at the governor’s mansion. The governor’s wife, Lucretia, hosted Sextus while the governor was away at war. During the night, Sextus entered her bedroom and raped her. The next day, Lucretia traveled to her father, Spurius Lucretius, a distinguished prefect in Rome, and, before witnesses, informed him of what had happened. Because her father was a chief magistrate of Rome, her pleas for justice and vengeance could not be ignored. At the end of her pleas, she stabbed herself in the heart with a dagger, ultimately dying in her own father’s arms. The scene struck those who had witnessed it with such horror that they collectively vowed to publicly defend their liberty against the outrages of such tyrants.

Lucius Junius Brutus, a leading citizen and the grandson of Rome’s fifth king, Tarquinius Priscus, publicly opened a debate on the form of government that Rome should have in place of the existing monarchy. A number of patricians attended the debate, in which Brutus proposed the banishment of the Tarquins from all territories of Rome, and the appointment of an interrex to nominate new magistrates and to oversee an election of ratification. It was decided that a republican form of government should temporarily replace the monarchy, with two consuls replacing the king and executing the will of a patrician senate. Spurius Lucretius was elected interrex, and he proposed Brutus, and Lucius Tarquinius Collatinus, a leading citizen who was also related to Tarquinius Priscus, as the first two consuls. His choice was ratified by the comitia curiata, an organization of patrician families who primarily ratified decrees of the king.

In order to rally the plebeians to their cause, all were summoned to a legal assembly in the forum, and Lucretia’s body was paraded through the streets. Brutus gave a speech and a general election was held. The results were in favor of a republic. Brutus left Lucretius in command of the city as interrex, and pursued the king in Ardea where he had been positioned with his army on campaign. Tarquinius, however, who had heard of developments in Rome, fled the camp before Brutus arrived, and the army received Brutus favorably, expelling the king’s sons from their encampment. Tarquinius was subsequently refused entry into Rome and lived as an exile with his family.

The Establishment of the Republic


Brutus and Lucretia. The statue shows Brutus holding the knife and swearing the oath, with Lucretia.

Although there is no scholarly agreement as to whether or not it actually took place, Plutarch and Appian both claim that Brutus’s first act as consul was to initiate an oath for the people, swearing never again to allow a king to rule Rome. What is known for certain is that he replenished the Senate to its original number of 300 senators, recruiting men from among the equestrian class. The new consuls also created a separate office, called the rex sacrorum, to carry out and oversee religious duties, a task that had previously fallen to the king.

The two consuls continued to be elected annually by Roman citizens and advised by the senate. Both consuls were elected for one-year terms and could veto each other’s actions. Initially, they were endowed with all the powers of kings past, though over time these were broken down further by the addition of magistrates to the governmental system. The first magistrate added was the praetor, an office that assumed judicial authority from the consuls. After the praetor, the censor was established, who assumed the power to conduct the Roman census.