
Map of the Second Triumvirate: red is Octavian's Rome, yellow is Lepidus' Rome, and white is Antony's Rome
The Second Triumvirate was the political alliance which ruled the Roman Republic from 43 to 33 BC, consisting of Gaius Octavius, Mark Antony, and Marcus Aemilius Lepidus. Octavian was the adopted son and sole heir of Julius Caesar; Antony was Caesar's right-hand man and a veteran of his campaigns; and Lepidus was a cavalry commander who served as governor of Transalpine Gaul. The three of them decided to join forces to fight against Caesar's assassins, the Liberatores, and they shared responsibilities by dividing the Roman Republic into three realms: Octavian ruled Gaul, Hispania, and Italia; Lepidus ruled North Africa; and Antony ruled over Rome's eastern provinces. In 33 BC, Lepidus was pushed out after he demanded that Sicily be added to his domain due to his unrewarded participation in the war against Sextus Pompey, as Octavian claimed that he was inciting unrest. Antony and Octavian would become fierce rivals, leading to war and the Battle of Actium in 31 BC; Antony was forced to flee to Ptolemaic Egypt, the land of his lover and ally Queen Cleopatra, where both of them committed suicide in 30 BC as Octavian's army invaded. In 27 BC, the Roman Senate named Octavian - now the sole ruler of the Roman Republic - as Princeps, inaugurating the Roman Empire.
History[]
Assassination of Caesar[]

The Liberatores washing their hands in Julius Caesar's blood
On 15 March 44 BC, the Roman dictator Julius Caesar was assassinated by a conspiracy of Roman senators led by Marcus Junius Brutus and Gaius Cassius Longinus. The conspirators, known as the Liberatores, saw their actions as a justified tyrannicide, fearing that Caesar would have eventually declared himself King. On 17 March 44 BC, Caesar's right-hand man Mark Antony met with the Liberatores at the Roman Senate to agree to a compromise: Caesar would neither be declared a tyrant nor his killers declared murderers, Caesar's will would stand, everyone would keep their posts, and Brutus and Antony would hold a public funeral for Caesar and speak together. Brutus and Cassius agreed, as declaring Caesar a tyrant would nullify the vast amount of favors that he showered upon the Senate, including themselves. The hypocritical Brutus and Cassius agreed to the compromise, and the Roman Senate issued an amnesty for Caesar's killers.

A few days later, Antony called for Caesar's will to be read, as he believed that he - Caesar's trusted lieutenant for years - would be the childless Caesar's obvious choice for his heir. However, Caesar's great-nephew Octavian had become close to Caesar during his campaigns in Hispania during the civil war with Pompey, and Caesar secretly adopted Octavian as his son and heir. In the will, he left all of his property and money to Octavian, who was to be regarded as Caesar's lawful son and sole heir. Octavian, who came from a plebeian family with ties to Caesar, was in Illyricum at the time of the assassination of Julius Caesar, but he rushed to Rome after discovering his inheritance. Caesar's posthumous adoption of Octavian challenged Antony's leading role in the Caesarian movement, although Antony still enjoyed the love of the people.
Caesarian power struggle[]

Antony speaking to the crowd at the funeral
On 20 March 44 BC, Antony spoke at Caesar's funeral, where he manipulated the Roman public's emotions to turn popular sentiment against the Liberatores. Antony's speech incited riots against the Liberatores, who were forced to barricade themselves indoors to prevent themselves from being murdered. As Octavian neared Rome, the Liberatores fled from the capital, fearing civil war. Antony was able to consolidate his power as the head of the Caesarian movement, and the conflict between Octavian and Antony began after Antony - who was in sole possession of Octavian's inheritance - continued to delay the transfer of the vast sums of money to Octavian. Antony pointed out that Caesar's adoption was unofficial, and he attempted to delay transferring the inheritance for as long as possible. However, Antony also neglected to pay Caesar's veterans their share of the money. Octavian borrowed an immense amount of money to fulfill these bequests, even selling Caesar's private lands and estates, and this move won the hearts and minds of Caesar's old legions for Octavian, who was now seen as his true heir due to his fulfilling of Caesar's promises.

With the battle lines being drawn, the influential politician Cicero launched a smear campaign against Antony in the Senate, giving a series of speeches called the "Philippics" which demonized Antony as a threat to Rome. Antony's popularity was waning and his consulship was nearing its end, so he made plans to protect his future. Unhappy with his posting as Governor of Macedonia, he pushed the Senate to name him as Governor of Cisalpine Gaul in northern Italia, from which he could easily swoop down to Rome if he was ever threatened. However, Decimus Junius Brutus Albinus, one of Caesar's assassins, was already governor in Cisalpine Gaul, and the Senate refused to depose him. Antony had little choice but to take his army and invade Italia, marching his veteran Caesarian legions from Macedonia and into Italy.
Battle of Mutina[]

Antony marching on Mutina
On 28 November 44 BC, Antony left Rome with four veteran legions that had crossed from Macedonia to Brundisium, but one of his legions defected to Octavian, refusing to fight for him. Antony took his three remaining legions and laid siege to Brutus at Mutina (now Modena). On 1 January 43 BC, the Senate declared Antony to be an enemy of the state and turned to Octavian for military support. Cicero believed that he could manipulate Octavian and discard him once he had served his purpose, and Octavian oddly fought side-by-side with one of Caesar's assassins.
On 14 April 43 BC, the Roman consul Gaius Vibius Pansa Caetronianus marched north from Rome to reinforce Octavian and his fellow consul Aulus Hirtius during Antony's siege, but Antony attacked Caetronianus' army at Forum Galliorum. Vibius Pansa was mortally wounded, and Antony called off the pursuit of his broken army. However, Hirtius' fresh troops crashed into Antony's exhausted army, devastating Antony's forces. Antony and his cavalry pulled back to his camp, having lost the initiative and the battle.

Octavian riding into battle
Six days later, on 21 April 43 BC, Hirtius and Octavian attacked Antony's army with the goal of opening a supply route to the city. Antony sent two legions to hold back the Republican advance, and the Antonian forces struggled due to the slow arrival of their reinforcements. During the battle, Hirtius himself led an attack on Antony's camp, but he was killed while vainly attempting to attack Antony's command tent. Octavian managed to recover Hirtius' remains, but could not keep possession of Antony's camps. Octavian assumed command of Hirtius' legions and refused to transfer command of the legions to Brutus, saying that they would never fight for one of Caesar's assassins. Octavian came to be in control of eight legions loyal to him and not to the Republic, and Brutus' legions at Mutina began to desert to Octavian. Brutus soon abandoned his remaining legions and fled Italy, only to be captured and executed by a Gallic chieftain loyal to Antony before he could reach Brutus and Cassius in Macedonia.
Formation of the Triumvirate[]

The Second Triumvirate enacting the proscriptions
Antony was forced to retreat into Gaul with the remnants of his army, and he met up with his old comrade Marcus Aemilius Lepidus, the governor of Transalpine Gaul. Lepidus had been sent with an army to finish off Antony, but Lepidus engaged in negotiations instead. In July 43 BC, Octavian returned to Rome at the head of an army, and he forced the Senate to accept him as the new Consul. He proceeded to declare Brutus and Cassius as enemies of the Republic, proving to Cicero that he had underestimated Octavian. Cicero then sent a letter to Brutus warning him of Octavian and Antony's infighting, asking them to liberate Rome from tyrants once more. Brutus and Cassius brought 17 legions to liberate Rome, so Octavian formed the unlikely Second Triumvirate with Antony and Lepidus, allying against the Liberatores.

Before they could fight the Liberatores in battle, the triumvirs decided to enact a horrific policy to consolidate their power, the proscriptions. They wrote down the names of the most prominent supporters of Brutus and Cassius left in Rome, stripping them of their rights and protections under Roman law; their property would be confiscated and they would be named enemies of the state. Citizens who murdered proscribed people on the list would be rewarded, and the wealthy patricians' goods would be confiscated. Cicero was one of the most prominent names on the list, placed by his enemy Antony. On 3 and 23 October 42 BC, the combined armies of the triumvirs faced the Liberatores at the Battle of Philippi in Macedonia. On the first day, Cassius committed suicide as his legions were overrun, mistakenly believing that the same was happening with Brutus' legions, when, in fact, Brutus' forces were overwhelming Octavian's forces. Brutus held on for three weeks, and, on 23 October, he launched a massive assault against the Caesarians, which failed; Brutus proceeded to himself commit suicide. The deaths of Brutus and Cassius effectively set into motion the death throes of the Roman Republic, and Caesar was deified.

The triumvirs dividing the Republic
Following the victory at Philippi, the triumvirs officially legalized their power by dividing responsibilities. Octavian would rule Gaul, Hispania, and Italia; Lepidus would have Africa; and Antony would rule the rich eastern provinces. In 41 BC, Antony met the Ptolemaic Egyptian queen Cleopatra at Tarsus, and she seduced Antony aboard her lavish galley before forming a close relationship with him. Antony campaigned against the Parthians and Armenians in the east, while Octavian had to deal with Sextus Pompeius' Sicilian revolt. Sextus' Pompeian forces took over Sicily and used it as a base to commit piracy, blockading Rome from 39 to 36 BC and causing grain shortages. There were even reports of cannibalism in Rome, and it was ultimately dealt with at the Battle of Naulochus.
Fall of the Triumvirate[]

In 33 BC, Lepidus, who had raised 14 legions for the war with the Pompeians and been the first general to land in Sicily, demanded that Sicily be absorbed into his own realm and not Octavian's, as he felt that Octavian was treating him as a subordinate and not an equal. Octavian responded by accusing Lepidus of attempting to foment rebellion and usurp power, and Lepidus was humiliated when his own legions defected to Octavian. Lepidus was stripped of all of his offices but Pontifex Maximus, and he was exiled to Circeii.
In the following years, Octavian and Antony had grown accustomed to insulting each other's character and political authority in public. Antony accused Octavian of being a usurper, of being Caesar's receiving partner in a gay relationship, and of never taking part in any battle personally. Octavian accused Antony of having no moral virtues (as Antony was a notorious drinker and a sexual deviant), especially after Antony left his sister Octavia the Younger to be with Cleopatra, under whom he became Egyptianized and was no longer a proud Roman. In the end, Octavian claimed to have Antony's will and testament, which would divide Rome's eastern provinces among the children he sired with Cleopatra, which recognized Cleopatra's son Caesarion as Caesar's legitimate successor, and which would have Antony be buried in Alexandria and not Rome. This shocked and outraged the public, and Octavian convinced the Roman people and Senate to declare war on Antony.

The Battle of Actium
Antony and Cleopatra mobilized their navy with the goal of conquering Rome, but they were forced to divert to Greece during a storm. Octavian's fleet destroyed Antony and Cleopatra's fleet at the Battle of Actium on 2 September 31 BC, and they returned to Alexandria, barricaded themselves inside the Ptolemaic Royal Palace, and waited for the arrival of Octavian's army for a year. Octavian besieged Alexandria in 30 BC, sending a messenger to Antony; Antony told the messenger that he sought to challenge Octavian to single combat, but the offer was refused. Cleopatra sought to save her life and those of her children by sending a fake suicide note to Antony, who stabbed himself in despair; he survived the attempt, and was ultimately brought to Cleopatra, dying in her arms. Cleopatra was allowed to preside over Antony's funeral, and she attempted to charm Octavian shortly after. Cleopatra begged for her life, and Octavian took the pitiful display as proof that she wanted to live. Octavian said that he would spare her life if she accompanied him to Rome, but she knew that she would face a humiliating death, so she deceived Octavian by accepting his terms before having a poisonous snake bite her and kill her.
Imperator Augustus[]
Octavian was forced to proceed to his triumph without Cleopatra, using an effigy of her at his victory celebrations in Rome. Cleopatra's death ended the Ptolemaic dynasty and ushered in the Roman rule of Aegyptus, and Octavian ushered in the Pax Romana, a 200-year period of peace and stability. In 27 BC, he changed his name to "Augustus", and he was named Princeps, the first ruler of the Roman Empire.