The Battle of Actium, September 2, 31 BC.

The Battle of Actium, fought on 2 September 31 BC in the Ionian Sea near Actium, was the decisive conflict of the civil war between Octavian Caesar (later known as Augustus) and the combined forces of Mark Antony and Cleopatra VII of Egypt. This battle marked the end of over a decade of rivalry between Octavian and Antony, which began after the assassination of Julius Caesar in 44 BC.

Background

In 60 BC, Julius Caesar, Marcus Licinius Crassus, and Pompey the Great formed the First Triumvirate, dividing control of Rome’s territories among themselves. However, Crassus was killed during a campaign against the Parthians in 53 BC. With Crassus gone, the rivalry between Caesar and Pompey escalated into civil war (49-45 BC). Pompey sought refuge in Egypt but was assassinated on the orders of Ptolemy XIII, Cleopatra VII’s younger brother, who believed Caesar would appreciate the gesture. Instead, Caesar reinstated Cleopatra as queen, leading to the death of Ptolemy. Caesar and Cleopatra then became lovers, and she gave birth to their son, Caesarion. In 46 BC, Caesar brought Cleopatra and Caesarion to Rome, publicly acknowledging her as his consort and Caesarion as his son. This move angered the Roman Senate, who believed Cleopatra had bewitched Caesar.

However, Caesar’s heir, Octavian, distrusted Cleopatra, fearing Caesarion could challenge his claim. After Caesar’s assassination in 44 BC, Cleopatra fled to Egypt, and Octavian allied with Antony and Lepidus in the Second Triumvirate, defeating Brutus and Cassius. Octavian then returned to Rome, while Antony summoned Cleopatra in Tarsus to answer charges of supporting Brutus and Cassius. The two quickly became lovers, and Antony remained in the east.

In 41 BC, Antony’s younger brother, Lucius Antonius, led a revolt against Octavian, which was swiftly suppressed. In response, Antony allied with Sextus Pompey, the son of Pompey the Great. Instead of engaging in battle, Octavian made peace with Antony, who agreed to marry Octavian’s sister, Octavia. Antony eventually broke his alliance with Sextus, who was defeated in 35 BC by Octavian, Marcus Vipsanius Agrippa, and Lepidus. Lepidus tried to claim the victory for himself by attempting to annex Sicily to his territories. This move was strongly opposed by Octavian, who then expelled Lepidus from the Second Triumvirate.

With Lepidus out of the picture, Octavian and Antony became the two dominant powers in Rome. However, Antony lost support in Rome by divorcing Octavia, marrying Cleopatra, and declaring Caesarion as "King of Kings." This led to a complete break with Octavian, and in 33 BC, Antony informed the Senate that he would not seek reappointment as a triumvir, effectively ending the Second Triumvirate. To win public favour, Octavian framed Antony as a traitor, claiming that if he gained power, he would hand Rome over to Cleopatra and relocate the centre of Roman power to Alexandria. As a result, the Senate revoked Antony’s authority as both triumvir and consul, citing national security threats due to his perceived submission to Cleopatra. To avoid alienating Antony’s remaining supporters, they declared war on Cleopatra, casting Octavian as the defender of Rome and subtly implying the need to "rescue" Antony from her influence. Octavian knew Antony would never abandon Cleopatra or accept a subordinate position, thus ensuring Antony’s self-condemnation as an enemy of the state.

The Battle

Antony and Cleopatra prepared their army and fleet at Ephesus (modern-day Turkey), wintering there from 33-32 BC. Antony’s officers, aware of Octavian’s strategy, urged him to distance himself from Cleopatra by sending her back to Egypt and negotiating with Octavian, but he refused. By August 32 BC, their forces had moved north to Actium on the Ionian Sea, with an army of 19 legions, 10,000 light-armed troops, and 12,000 cavalry, wintering there with supplies from Egypt. Meanwhile, Octavian mobilised 80,000 infantry, 12,000 cavalry, 3,000 archers, and over 400 ships, led by his general Agrippa. In early 31 BC, Octavian positioned his land forces north of Actium, fortifying his camp, while Agrippa continued to cut off supplies by taking Leucas. Facing starvation, Antony and Cleopatra planned to engage in naval combat and, if unsuccessful, flee to Egypt. On September 2, 31 BC, they moved their fleet into the Ionian Sea, hoping the wind would push Agrippa’s ships away from their camp and allow their land forces to attack. However, Octavian, informed by deserters that Antony and Cleopatra intended to escape to Egypt rather than fight, prepared his fleet. Agrippa arranged his ships in three formations, negating the advantage Antony hoped the wind would provide.

At noon, with the wind in his favour, Antony launched his slow-moving quinqueremes toward Agrippa’s faster Liburnians, hoping to turn Agrippa’s left flank. However, Agrippa’s ships outmaneuvered the quinqueremes, sinking 15 of Antony’s vessels. As Agrippa’s ships rammed and disabled the larger quinqueremes, Antony’s fleet became static fortresses, unable to counter the quicker ships. As the battle progressed, three of Antony's squadrons retreated, and two others surrendered. Realising the battle was lost, he and Cleopatra fled to Alexandria.

Aftermath

When Octavian arrived outside Alexandria in July 30 BC, Antony was jolted out of his despair. By August 1, most of Antony’s men had deserted and that afternoon, he stabbed himself. Octavian entered the city and presented Cleopatra with terms she had no choice but to accept. On August 30, 30 BC, rather than be paraded as a trophy in Rome, she took her own life. Octavian honored the wishes of Antony and Cleopatra to be buried together and ordered the execution of Caesarion.

Octavian was celebrated as Rome’s saviour and bolstered his standing by directly controlling Egypt. To gain favour with Cleopatra's former subjects, he accepted the honours and title of a Ptolemaic pharaoh. In January 27 BC, aware of the dangers of appearing overly ambitious like Julius Caesar, he resigned his powers, only to have the Senate restore them and bestow upon him the title Augustus. Octavian accepted, becoming Augustus Caesar, the first emperor of the Roman Empire.