Why did the war of Actium break out?
The traditional answer is to focus on Cleopatra. But there are, as ever, problems with the traditional answer.
Representations of the war from the Augustan period onwards tend to emphasise the role played by Cleopatra. Octavian’s war is seen as for Italy against the East; for Roman values against Egypt; for traditional masculinity against a tyrannical woman. We can see such presentations in the poets, such as Propertius, 3.11 and 4.6, Horace, Odes 1.37, and Virgil, Aeneid 8. 671-713.
None of those poetic incidents are entirely straightforward. Propertius’ poetry is framed by his overwhelming romantic entanglement with Cynthia, and if Cynthia dominates his life, the parallels between the poet and his girl and Antony and his girl confuse any patriotic outbursts.
For Virgil, the extremes of the celebration of Actium are located on a work of art that Aeneas, the hero of the piece, himself does not understand. The art simplifies and Virgil makes us think about what we would now call propaganda and its simplification of truth.
Horace is perhaps the most straightforward, but even here, the context of a heavy-drinking celebration removes us from the battlefield to a domestic safety.
Octavian seems to have emphasised the Italian versus the Egyptian at Actium. He arranged for ‘All Italy’ to take an oath of loyalty to him in the war, but the importance of the oath is not clear (Res Gestae 25). Even if it was the equivalent of a military oath, it is not obvious that Octavian was mobilising Italy in a Great Patriotic War.
In the immediate circumstances of the outbreak of the war, Octavian stressed the importance of Cleopatra (Dio, 50.1-6). According to our third-century AD source, Dio, there was a concerted attempt to show that Antony was assimilating to Greek-Egyptian modes of behaviour and perhaps even to present Cleopatra as controlling Antony.
Antony’s position is reflected in an extract from a letter he wrote to Octavian, which often has more polite translations:
What’s happened with you? Because I enter the queen? She is my wife. Did I begin this now or nine years ago? Do you then enter only Drusilla? Good luck to you if as you read this letter you have not entered Tertulla or Terentilla or Rufilla or Salvia Titisenia, or all. What does it matter where and in whom you are pleasured?
At best, this letter might be seen as disingenuous. It is surely right that Cleopatra was not a new political factor and that Octavian had not been exercised over Antony and Cleopatra’s relationship previously. But it clearly mattered that Cleopatra and Antony had formed a household together or the Donations of Alexandria would never have happened.
The story in Dio (50. 1-4) is of increasing levels of tension between Antony and Octavian. It was sparked into conflict in January 32 when the two consuls, Gnaeus Domitius and Gaius Sosius, both Antony’s men, took up office. Sosius made an inflammatory speech attacking Octavian. Octavian was not in Rome, but the speech was reported to him. He returned to the city, called a meeting of the senate, and attended with an armed guard. He spoke against the consuls and Antony. The consuls fled. At this point, various prominent Romans changed sides, some going to Antony, some coming to Octavian.
But there was still no cause for war. Octavian was told by the defectors that Antony’s will was in the keeping of the vestals in Rome. He secured the will and read its contents before the senate.
In many ways, the will was not exceptional. Antony left large bequests to his children. He said that he wished his ashes to be buried alongside Cleopatra. But what seems to have caused an uproar was a perception that Antony wished to move the centre of government to Alexandria, though this was not stated in the document. This ran contrary to a supposed fear that Cleopatra was intending to administer justice in Rome, but logic and civil wars are not easy bedfellows.
So what was the problem?
- It is unlikely that any formal move of governmental structures was envisaged. It is not clear what would be involved in establishing Alexandria as an alternative centre of the Empire.
- Because Antony was already based in Alexandria, there was a recognition that Alexandria was becoming the second city in the political organisation of the empire.
- Antony’s relationship with Cleopatra presupposed a long-lasting political domination of the East by Antony, Cleopatra and their children. One consequence of such an arrangement was the long-term importance of Alexandria.
- Rome benefited considerably from the flows of wealth through the city from the Empire. Any diversion of that wealth and power through Alexandria was unlikely to be welcomed by the Italian senatorial aristocracy.
Yet
- There was no real threat of Antony returning west, displacing Octavian, and less still of him imposing Queen Cleopatra on the Romans.
- There was no immediate crisis.
One struggles to find anything approximating a plausible justification for war. Also, neither side seems to have been ready for war. Although serious political problems emerged in January 32 and there was some military skirmishing in late 32, the war of Actium began in earnest only in 31.
But we may be reading these events with modern political eyes.
The Romans tended to solve problems by going to war. Faced with almost any real or imagined foreign policy problem, their response was violence. Although civil wars were different, after fifty years of repeating incidents of internal military conflict, perhaps civil war was also easily begun.
Actium
The war broke out seriously in 31 BC. Antony dashed his fleet and army towards the West. Octavian crossed the Adriatic with his legions and the two powers met at Actium in what is now Western Greece.
The Gulf of Actium was one of the few very good harbours in North-Western Greece. It was a strategic spot from which Antony could gather his strength and prepare to launch an invasion of Italy. But Antony was out-manoeuvred by Agrippa. He established his base at Lefkada. From there he was able to disrupt Antony’s supply lines from the South and East, while Octavian and his legions controlled the north bank of the Gulf.
If the sea routes to the Gulf were superb, the land routes were terrible. Antony was also encamped on low-lying, marshy ground in the height of summer. His troops sickened. With his army short of supplies and suffering from disease, Antony had no choice but to fight his way out.

Low land in the Gulf of Actium
The extended description of the war in Dio (50.15-35) has debates among the Antonians as to what to do, debates which were won by Cleopatra (scandalously) who argued for a naval battle. But if there was a debate and Cleopatra was the decisive voice, then she was the one who spoke sense.
Escape by sea was the only possibility and naval battle which either defeated Agrippa and gave the Antonians naval supremacy or allowed the Antonians to regroup and fight another day was the best chance they had.
The battle itself was attritional and slow moving. The key was not to allow the opponent to break up the lines of ships in which circumstances individual ships might get surrounded and captured. Artillery was used to pound the other side. But neither side gained an advantage.
One of the features of the coastline here is that the wind comes up in the afternoon. The Antonian options were limited. If the battle was indecisive, they could not easily return to harbour and wait another day. They had either to defeat Agrippa or make an escape. It seems possible that the Antonian plan was to make enough space so that when the wind rose, they could hoist sail and depart, if the battle had not been won. Given the simplified logic, the Octavian and Agrippa would be able to make those calculations. If they could keep the Antonian fleet engaged through the afternoon, they would win.
It seems that the Antonian plan half worked. When the wind rose, Cleopatra gave the signal, the sails were hoisted and her flotilla and Antony’s group fled. They made good their escape. But many of the ships were caught. Some may have been fighting a rearguard action so that Antony and Cleopatra could make good their escape. The fact that they did not give up as soon as Antony and Cleopatra had disappeared over the horizon and continued through the afternoon to battle their way out suggests that they had hopes of achieving the planned retreat.
But eventually they were hemmed in. Agrippa and Octavian fired burning pitch at the Antonian ships. They caught fire and the fleet burned.