Octavian and the Second Triumvirate


The Fall of the Roman Republic

The Second Triumvirate was formed by Octavian, Marc Antony and Marcus Aemilius Lepidus in Bologna in October, 43 BC. 

After becoming Consul, Octavian met in Bologna in October, 43 BC with Mark Antony and Marcus Aemilius Lepidus, where they formed the Second Triumvirate. Unlike the First Triumvirate, the Second Triumvirate was an explicit arrangement of special powers intended to last for five years and passed into law by the Roman Tribunes. The Triumvirs then set a series of proscriptions in motion. As a result of these proscriptions, 2,300 Roman senators and aristocrats were forced to flee. These proscriptions were motivated by the need of the Triumvirs to raise money for the coming conflict with Caesar’s assassins.

The Second Triumvirate

In January, 44 BC, the Senate posthumously deified Julius Caesar. Octavian used his connection with Julius Caesar to enhance his position, calling himself Divis filius, or the Son of God.

Octavian vs Brutus

In October, 42 BC, Octavian sent an army of 28 Legions to Greece where Brutus and Cassius, the architects of Caesar’s assassination had established a power base. Following two decisive defeats at Phillipi, in Macedonia, both Brutus and Cassius committed suicide.

Following these battles, a new territorial arrangement was reached by the Triumvirs. Antony was given the east, Octavian was given was the west and Lepidus was given Africa. After this, Antony travelled to Egypt, where he allied himself with Cleopatra. Meanwhile, Octavian was left to settle the issue of where to settle the veterans of the Macedonian campaign, in addition to the centurions who had fought for Brutus and Cassius. Matters were complicated by the fact that there was no government land left, on which Octavian could settle the disbanding Legions. He faced the prospect of alienating many Roman citizens, or alienating tens of thousands of veterans who could provide his enemies with the troops needed to force him out of power. In the end, Octavian chose the former. The primary sources indicate that at least 18 Roman towns were affected by the settlement of the Legions.

Octavian vs Lucius Antonius

Widespread resentment over Octavian’s actions drove many of his enemies into the camp of Lucius Antonius, the brother of Marc Antony. At the same time, Octavian sought to divorce Clodia Pulchra, the daughter of the Roman Senator Publius Claudius Pulcher. Antonius, and Clodia’s mother, Fulvia, raised an army with the intent of opposing Octavian. Octavian was eventually able to trap Antonius at Perusia. Octavian spared Antonius because of his kinship with Mark Antony, but had 300 Senators and other allies of Antonius put to death. Octavian also formed an alliance with Sextus Pompieus who was given control of Sicily in 40 BC.

Around the same time, Antony was engaged in an affair with Cleopatra. Antony was also aware that his relationship with Octavian was badly strained. In 40 BC, he returned to Italy, laying siege to Brundisium. This proved to be a misstep for both Antony and Octavian, as their Legions mutinied and refused to fight. This led to the Treaty of Brundisium, which cemented the Triumvirs’ earlier arrangement and left Italy neutral for the recruitment of new Legions.

Octavian vs Sextus Pompeius

Meanwhile, rebellion was brewing in Sicily. Sextus Pompeius cut off the grain shipment to Italy in an attempt to turn Rome against Octavian. In 39 BC, a temporary truce was reached and Sextus was given Corsica, Sicily and the Peloponnes, which would ensure his election as Consul in 35 BC. However, he was betrayed by one of his admirals, who handed over Corsica and Sardinia to Octavian. This resulted in the Second Triumvirate being extended for another five years.

In 36 BC, Octavian and Lepidus attacked Sextus in Sicily. Despite a number of setbacks, Octavian’s admiral, Agrippa, was able to sink most of Sextus’s fleet. Sextus was eventually captured and executed in Miletus. Lepidus was exiled to a villa near Cape Circei after he tried to use Sextus’ Legions to seize Sicily.

Octavian vs Antony

Meanwhile, Antony’s campaign in Parthia had turned into a disastrous failure. Antony turned to Cleopatra to replenish his forces, which provided fuel for Octavian’s propaganda machine. In 36 BC, Octavian used a political trap to cast himself in a better light, when he offered to step aside as Triumvir if Antony did the same. Antony refused.

In January, 33 BC, Octavian was elected Consul again. He used his power to convince the Senate that Antony intended to diminish Rome’s position. In 32 BC, the Senate stripped Antony of his consular authority and declared war on Egypt.

In 31 BC, Octavian scored a tactical victory when he successfully landed his troops on the Greek island of Corfu and began to march south, trapping Antony and Cleopatra, while Agrippa cut them off from the sea.

In a desperate attempt to break the Roman blockade, Antony engaged Octavian’s fleet at Actium. Following a second defeat at Alexandria, Antony and Cleopatra committed suicide, allowing Octavian to set himself up as Rome’s first Emperor.


Chisholm, Kitty and John Ferguson. (1981). Rome: The Augustan Age; A Source Book. Oxford: Oxford University Press, in association with the Open University Press.

Dio, Cassius (1987) The Roman History: The Reign of Augustus. Translated by Ian Scott-Kilvert. London: Penguin Books.

Everitt, Anthony (2006) Augustus: The Life of Rome’s First Emperor. Random House Books.

Mackay, Christopher S. (2004). Ancient Rome: A Military and Political History. Cambridge University Press.

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