Battle of Philippi

Two years after the killing of Julius Caesar, the men who had led the plot, Brutus and Cassius, met the armies of Caesar's avengers, Mark Antony and Octavian, on the plain west of Philippi in eastern Macedonia, in what is now northern Greece. The fighting came in two separate engagements in October 42 BC, conventionally dated 3 and 23 October. Both Cassius and Brutus took their own lives, and with them the last serious republican challenge to the triumvirs collapsed.

After the assassination of Julius Caesar in 44 BC, Brutus and Cassius, who called themselves the Liberators, left Italy and made themselves masters of the Roman East, from Greece to Syria. In Rome, Antony, Octavian and Lepidus overcame the Senate and formed the Second Triumvirate, with the aim of destroying the Liberators and taking control of the Roman world.

Lepidus stayed in Italy while Antony and Octavian crossed the Adriatic with 28 legions. The Liberators, who had raised money by plundering Greek cities, preferred to dig in on high ground astride the Via Egnatia, protected by hills on one side and marsh on the other, and to let their stronger fleet cut the triumvirs off from Italy. Brutus camped north of the road and Cassius south of it.

The triumvirs had nineteen legions and 13,000 allied cavalry; the Liberators had seventeen legions and 20,000 horsemen. No ancient writer gives full totals. Estimates range widely, from about 40,000 to 50,000 legionaries on each side to perhaps 95,000 and 85,000 at full strength, making it one of the largest battles of the Roman civil wars.

Antony, unable to tempt the Liberators down, secretly built a causeway through the marsh to get round Cassius's flank. Cassius tried to cut it off, and on 3 October a general battle broke out. Brutus's men attacked Octavian's wing without orders and overran his camp; Octavian, who was ill, was not there, and the ancient sources variously say he had been warned in a dream or had hidden in the marsh. On the other side of the road, Antony stormed Cassius's fortifications and took his camp.

The result was roughly even. Cassius reportedly lost about 8,000 men and Octavian about 16,000. But in the dust and confusion Cassius believed Brutus had been beaten as well and had his freedman kill him.

On the same day the republican fleet destroyed triumviral reinforcements at sea, and the triumvirs' supply position grew dangerous. Over the next three weeks, however, Antony gradually extended his lines southward and eastward, threatening to cut Brutus off from his supply port. Brutus, less experienced than Cassius, with restless troops and some allies deserting, attacked on the afternoon of 23 October.

The fighting was at close quarters and very bloody. Brutus did well on his western wing, but his line had been stretched too thin, and the triumvirs broke through in the centre and turned his flank. Octavian's soldiers reached Brutus's camp first. Brutus escaped to the hills with the remains of about four legions and then killed himself.

According to Plutarch, Antony honoured Brutus's body by laying a purple garment over it. Many young aristocrats died in the battle or by suicide, including a son of Cato the Younger. About 14,000 of the defeated soldiers were taken into the triumvirs' army, and Philippi became a Roman colony settled by veterans. Antony stayed in the East as the leading figure of the triumvirate, while Octavian returned to Italy to find land for the veterans. The rivalry between the two would end at the Battle of Actium and in the end of the Roman Republic.

The story of Brutus's ghostly visitor, who promised to see him again at Philippi, comes from Plutarch and was made famous by Shakespeare's Julius Caesar.

Our 1 BCE map shows Macedonia, in modern Greece, as part of the Roman world after the civil wars; the nearest earlier map, -100, shows the republic before them.