Overthrow of the Roman monarchy

The Overthrow of the Roman monarchy was a political revolution in ancient Rome in around 509 BC, which resulted in the expulsion of the last king of Rome, Lucius Tarquinius Superbus, and the establishment of the Roman Republic.

The Roman histories tell that while the king was away on campaign, his son Sextus Tarquinius raped a noblewoman Lucretia. Afterwards, she revealed the offence to various Roman noblemen, and then committed suicide. The Roman noblemen, led by Lucius Junius Brutus, obtained the support of the Roman aristocracy and the people to expel the king and his family and to institute a republic. The Roman army supported Brutus, and the king went into exile. Despite a number of attempts by Lucius Tarquinius Superbus to reinstate the monarchy, the republic was established and two consuls were elected annually to rule the city.

• Background: The Kingdom

Roman history held that seven kings of Rome reigned from the establishment of the city in 753 BC by Romulus up to the reign of Tarquinius. The accuracy of this account has been doubted by modern historians, although it appears to be accepted that there was a monarchy, and the last king Tarquinius was expelled upon the founding of the republic in the late 6th century BC.

Tarquinius was the son of the fifth king, Lucius Tarquinius Priscus. In around 535 BC Tarquinius, together with his wife Tullia Minor (one of the daughters of the then king Servius Tullius) arranged the murder of Servius, and Tarquinius became king in his place.

Despite various military victories, Tarquinius became an unpopular king. He refused to bury his predecessor, then put to death a number of the leading senators whom he suspected of remaining loyal to Servius (one of whom was the brother of Lucius Junius Brutus). By not replacing the slain senators, and not consulting the Senate on all matters of government, he diminished both the size and authority of the Senate. In another break with tradition, he judged capital criminal cases without advice of counsellors, thereby creating fear among those who might think to oppose him. He also engaged in treachery with the Latin allies.

• Establishment of the republic

That uprising resulted in the exile or Regifugium, after a reign of 25 years, of Tarquinius and his family, and the establishment of the Roman Republic, with Brutus and Collatinus (both related by blood to Rome's fifth king Lucius Tarquinius Priscus) as the first consuls.

Tarquinius and his two eldest sons, Titus and Arruns, went into exile at Caere.

According to Livy, Brutus' first act after the expulsion of Lucius Tarquinius Superbus was to bring the people to swear an oath never to allow any man again to be king in Rome.

Omnium primum avidum novae libertatis populum, ne postmodum flecti precibus aut donis regiis posset, iure iurando adegit neminem Romae passuros regnare.

First of all, by swearing an oath that they would suffer no man to rule Rome, it forced the people, desirous of a new liberty, not to be thereafter swayed by the entreaties or bribes of kings.

This is, fundamentally, a restatement of the 'private oath' sworn by the conspirators to overthrow the monarchy:

Per hunc... castissimum ante regiam iniuriam sanguinem iuro, vosque, di, testes facio me L. Tarquinium Superbum cum scelerata coniuge et omni liberorum stirpe ferro igni quacumque dehinc vi possim exsecuturum, nec illos nec alium quemquam regnare Romae passurum.

By this guiltless blood before the kingly injustice I swear – you and the gods as my witnesses – I make myself the one who will prosecute, by what force I am able, Lucius Tarquinius Superbus along with his wicked wife and the whole house of his freeborn children by sword, by fire, by any means hence, so that neither they nor anyone else be suffered to rule Rome.

There is no scholarly agreement that the oath took place; it is reported, although differently, by Plutarch (Poplicola, 2) and Appian (B.C. 2.119).

Brutus also replenished the number of senators to 300 from the principal men of the equites. The new consuls also created a new office of rex sacrorum to carry out the religious duties that had previously been performed by the kings.

Because of the Roman people's revulsion at the name and family of the exiled king, the consul Tarquinius Collatinus was forced to resign from the office of consul and go into exile.

• Attempts to reinstate the monarchy

After his exile, Tarquinius made a number of attempts to regain the throne. At first, he sent ambassadors to the Senate to request the return of his family's personal effects, which had been seized in the coup. In secret, while the Senate debated his request, the ambassadors met with and subverted a number of the leading men of Rome to the royal cause, in the Tarquinian conspiracy. The conspirators included two of Brutus' brothers-in-law, and his two sons Titus and Tiberius. The conspiracy was discovered, and the conspirators executed.

Although the Senate had initially agreed to Tarquin's request for a return of his family's effects, the decision was reconsidered and revoked after the discovery of the conspiracy, and the royal property was given over to be plundered by the Roman populace.

Tarquinius next attempted to regain Rome by force of arms. He first gained the support of the cities of Veii and Tarquinii, recalling to the former their regular losses of war and land to the Roman state, and to the latter his family ties. The armies of the two cities were led by Tarquinius against Rome in the Battle of Silva Arsia. The king commanded the Etruscan infantry. Although the result initially appeared uncertain, the Romans were victorious. Both Brutus (the consul) and Arruns (the king's son) were killed in battle.

Another attempt by Tarquinius relied on military support from Lars Porsenna, king of Clusium. The war led to the siege of Rome, and finally a peace treaty. However, Tarquinius failed to achieve his aim of regaining the throne.

Tarquinius and his family left Clusium, and instead sought refuge in Tusculum with his son-in-law Octavius Mamilius. In about 496 BC, Tarquin and his son Titus fought with Mamilius and the Latin League against Rome, but lost, at the Battle of Lake Regillus at which Mamilius perished.

Subsequently, Tarquinius fled to take refuge with the tyrant of Cumae, Aristodemus and Tarquin died there in 495 BC.