Treaty of Brundisium

The Second Triumvirate is the name historians have given to the official political alliance of Gaius Octavius (Octavian, Caesar Augustus), Marcus Antonius (Mark Antony), and Marcus Aemilius Lepidus, formed on 27 November 43 BC with the enactment of the Lex Titia, the adoption of which is viewed as marking the end of the Roman Republic. The Triumvirate existed for two five-year terms, covering the period 43 BC to 33 BC. Unlike the earlier First Triumvirate, the Second Triumvirate was an official, legally established institution, whose overwhelming power in the Roman state was given full legal sanction and whose imperium maius outranked that of all other magistrates, including the consuls.

Octavian, despite his youth, extorted from the Senate the post of suffect consul (consul suffectus) for 43 BC. He had been warring with Antony and Lepidus in upper Italia, but in October 43 BC the three agreed to unite and seize power and so met near Bononia (now Bologna).

This triumvirate of new leaders was established in 43 BC as the Triumviri Rei Publicae Constituendae Consulari Potestate (Triumvirs for Confirming the Republic with Consular Power, abbreviated as III VIR RPC). Where the first triumvirate was essentially a private agreement, the second was embedded in the constitution formally joining Augustus, Antony, and Lepidus in shared rule over Rome. The only other office which had ever been qualified "for confirming the Republic" was the dictatorship of Lucius Cornelius Sulla; the only limit on the powers of the Triumvirate was the five-year term set by law.

A historical oddity of the Triumvirate is that it was, in effect, a three-man directorate with dictatorial powers; it included Antony, who as consul in 44 BC had obtained a lex Antonia that abolished the dictatorship and expunged it from the Republic's constitutions. As had been the case with both Sulla and Julius Caesar during their dictatorships, the members of the Triumvirate saw no contradiction between holding a supraconsular office and the consulate itself simultaneously.

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