The Battle of Actium was the decisive confrontation of the Final War of the Roman Republic, a naval engagement between Octavian and the combined forces of Mark Antony and Cleopatra on 2 September 31 BC, on the Ionian Sea near the promontory of Actium, in the Roman province of Epirus Vetus in Greece. Octavian’s fleet was commanded by Agrippa, while Antony‘s fleet was supported by the power of Queen Cleopatra of Ptolemaic Egypt.
Octavian’s victory enabled him to consolidate his power over Rome and its dominions. He adopted the title of Princeps (“first citizen”) and some years later was awarded the title of Augustus (“revered”) by the Roman Senate. This became the name by which he was known in later times. As Augustus, he retained the trappings of a restored Republican leader, but historians generally view this consolidation of power and the adoption of these honorifics as the end of the Roman Republic and the beginning of the Roman Empire.
The alliance among Octavian, Mark Antony and Marcus Lepidus, commonly known as the Second Triumvirate, was renewed for a five-year term in 38 BC. However, the triumvirate broke down when Octavian saw Caesarion, the professed son of Julius Caesar and Queen Cleopatra VII of Egypt, as a major threat to his power. This occurred when Mark Antony, the other most influential member of the triumvirate, abandoned his wife, Octavian’s sister Octavia Minor, and moved to Egypt to start a long-term romance with Cleopatra, becoming the de facto stepfather to Caesarion. Such an affair was doomed to become a political scandal. Antony was inevitably perceived by Octavian and the majority of the Roman Senate as the leader of a separatist movement that threatened to break the unity of the Roman Republic.
During 32 BC one-third of the Senate and both consuls allied with Antony. The consuls had determined to conceal the extent of Antony’s demands. Gaius Sosius on 1 January made an elaborate speech in favor of Antony, and would have proposed the confirmation of his act had it not been vetoed by a tribune. Octavian was not present, but at the next meeting made a reply of such a nature that both consuls left Rome to join Antony; Antony, when he heard of it, after publicly divorcing Octavia, came at once to Ephesus with Cleopatra, where a vast fleet was gathered from all parts of the East, of which Cleopatra furnished a large proportion. After staying with his allies at Samos, Antony moved to Athens. His land forces, which had been in Armenia, came down to the coast of Asia and embarked under L. Canidius Crassus.
Octavian was not behind in his strategic preparations. Military operations began in 31 BC, when his general Agrippa captured Methone, a Greek town allied to Antony. However, by the publication of Antony’s will, and by carefully letting it be known in Rome what preparations were going on at Samos and how entirely Antony was acting as the agent of Cleopatra, Octavian produced such a violent outburst of feeling that he easily obtained Antony’s deposition from the consulship of 31 BC, for which Antony had been designated. In addition to the deposition, Octavian procured a vote for a proclamation of war against Cleopatra—well understood to mean against Antony, though he was not named. In doing this the Senate issued a war declaration and deprived Antony of any legal authority.
The two fleets met outside the Gulf of Actium (today Preveza) on the morning of 2 September 31 BC. Antony’s fleet numbered 500, of which 230 were large war galleys with towers full of armed men. He led these through the straits towards the open sea. Octavian had about 250 warships. His fleet was waiting beyond the straits, led by the experienced admiral Agrippa, commanding from the left wing of the fleet, Lucius Arruntius the centre and Marcus Lurius the right. Titus Statilius Taurus commanded Octavian’s armies, and he observed the battle from shore to the north of the straits. Antony and Gellius Publicola commanded the right wing of the Antonian fleet, while Marcus Octavius and Marcus Insteius commanded the center, with Cleopatra’s squadron positioned behind them. Gaius Sosius launched the initial attack from the left wing of the fleet, while Antony’s chief lieutenant Publius Canidius Crassus was in command of the triumvir‘s land forces.
Before the battle one of Antony’s generals, Quintus Dellius, had defected to Octavian, bringing with him Antony’s battle plans.
Shortly after midday, Antony was forced to extend his line from the protection of the shore and finally engage the enemy. Seeing this, Octavian’s fleet put to sea. Antony had hoped to use his biggest ships to drive back Agrippa’s wing on the north end of his line, but Octavian’s entire fleet, aware of this strategy, stayed out of range. By about noon the fleets were in formation but Octavian refused to be drawn out, so Antony was forced to attack. The battle raged all afternoon without decisive result.
Cleopatra’s fleet, in the rear, retreated to the open sea without engaging. A breeze sprang up in the right direction and the Egyptian ships were soon hurrying out of sight. Some historians argue that Antony would have been fighting with victory within reach if it were not for Cleopatra’s retreat.
Antony, believing that it was mere panic and all was lost, followed the flying squadron. The contagion spread fast; everywhere sails were seen unfurling and towers and other heavy fighting gear going by the board. Some fought on, and it was not until long after nightfall, when many a ship was blazing from the firebrands thrown upon them, that the work was done. Making the best of the situation, Antony burned the ships he could no longer man while clustering the remainder tightly together. With many oarsmen dead or unfit to serve, the powerful, head-on ramming tactic for which the Octaries had been designed was now impossible. Antony transferred to a smaller vessel with his flag and managed to escape, taking a few ships with him as an escort to help break through Octavian’s lines. Those left behind were captured or sunk.
A differing account of the battle is argued, postulating that Antony knew he was surrounded and had nowhere to run. To try to turn this to his advantage, he gathered his ships around him in a quasi-horseshoe formation, staying close to the shore for safety. Then, should Octavian’s ships approach his, the sea would push them into the shore. Antony foresaw that he would not be able to defeat Octavian’s forces, so he and Cleopatra stayed in the rear of the formation. Eventually Antony sent the ships on the northern part of the formation to attack. He had them move out to the north, spreading out Octavian’s ships, which up until this point were tightly arranged. He sent Gaius Sosius down to the south to spread the remaining ships out to the south. This left a hole in the middle of Octavian’s formation. Antony seized the opportunity and, with Cleopatra on her ship and him on a different ship, sped through the gap and escaped, abandoning his entire force.
With the end of the battle, Octavian exerted himself to save the crews of the burning vessels and had to spend the whole night on board. The next day, as much of the land army as had not escaped to their own lands, submitted, or were followed in their retreat to Macedonia and forced to surrender, Antony’s camp was occupied, bringing an end to the war.