Battle of Pharsalus

On August 9, 48 BC, Gaius Julius Caesar defeated Gnaeus Pompeius Magnus (Pompey) and the Senatorial forces at the Battle of Pharsalus and solidified his control over the Republic.

Prelude

Pompey and the Senate's army had left Italy for Greece, in 49 BC. Caesar, for lack of a fleet, solidified his control over the western Mediterranean — Spain and North Africa, specifically, before assembling ships to follow Pompey.

An indecisive winter (49–48 BC) of blockade and siege followed. Pompey eventually pushed Caesar into Thessaly and attacked at Pharsalus. Caesar began the battle with a smaller, but veteran, force. Pompey's troops were more numerous, but far less experienced. Moreover, Pompey's senatorial allies disagreed with Pompey over whether to fight at Pharsalus, and pushed Pompey into a quick decision.

After Pompey and the Roman Senate fled to Greece to avoid Caesar's invasion of Italy, they began to prepare an army to defend themselves in Greece. Caesar therefore marched overland through southern France meanwhile, blockading what is now Marseille, and managing to assemble a small fleet. After crushing Pompey's forces in Spain, Caesar focused once again on Pompey and his troops in Greece. Pompey had a fleet, as well as much support from all Roman provinces and client states east of Italy. Caesar, however, managed to cross the Adriatic in the winter, with Marc Antony following a little later because Caesar lacked ships. Although Pompey had a larger army, he recognized that Caesar's troops were more experienced, and could prove victorious in a pitched battle. Instead, Pompey waited Caesar's troops out, attempting to starve them by cutting off Caesar's supply lines. After a disastrous attack on Pompey's camp at Dyrrhachium, Caesar was forced to pull away. Pompey did not immediately follow up on his success; but urged on by his senatorial allies, he confronted Caesar near Pharsalus.

Caesar had the following legions with him:
* Legions of veterans from the Gallic Wars – Caesar's favourite legion, X Equestris, and those later known with the names of VIII Augusta, IX Hispana, and XII Fulminata
* Legions levied for the civil war – legions later known as I Germanica, III Gallica, and IV Macedonica

Battle

Both commanders realized that if one army was able to flank the other, they would probably win. As such, both commanders put a substantial amount of effort into ensuring that the other would be unable to 'sneak around to the back'. The battle was held with the River Enipeus to Caesar's left, ensuring that neither side would be able to move around the other army on Caesar's left. The most important part of the battle was to happen on Caesar's right. Pompey hoped to win by using his superior cavalry to mount a two-front attack on Caesar's forces. As such, he placed a large contingent of cavalry on Caesar's right, with light forces consisting of slingers (funditores) and archers (sagitarii). Caesar placed his cavalry on his right, with the fourth battle line in reserve behind it.

Deployment

Caesar opened the battle with three battle lines, and a fourth in reserve. Mark Antony was given command of Caesar's troops by the river. The center of Caesar's army was commanded by Domitius Calvinus. The commander of the right wing of Caesar's army was Publius Sulla, while Ahenobarbus commanded the right side of Pompey's force. Caesar was greatly-outnumbered in cavalry. To make matters worse for Caesar, the far-left wing of Pompey's army was commanded by Titus Labienus, who had been one of Caesar's legion commanders in Gaul, and knew Caesar better than any other general on the field that day. Light and heavy infantry were deployed near the river on both sides. The majority of the battle was a clash between heavy infantry.

Conflict

When the two generals had finished deploying their troops, the heavy infantry began to close. Pompey ordered his soldiers not to charge (against the standards of the day) in an effort to tire out Caesar's troops. This tactic backfired as Caesar's veteran centurions, foreseeing Pompey's trap, stopped halfway on their charge, and allowed their lines to rest, while Pompey's multi-lingual forces were unable to receive orders easily, leaving Pompey's troops confused, creating a stalemate in the center.

By the river, the light infantry skirmished, before the heavy infantry closed. Titus Labienus led a cavalry charge, and succeeded in pushing back Caesar's cavalry and light infantry. However, when confronted by Caesar's fourth line of heavy infantry, Labienus' charge was pushed back, and the light infantry and cavalry of Pompey's right were pushed into the foothills of Mount Dogandzis. Caesar's fourth battle line wheeled into Pompey's rear at the same moment when Caesar pushed a fresh line of troops into battle. Now facing Caesar's fresh third line at the center of the battle and the attack from behind from Caesar's fourth line, Pompey saw that his defeat was at hand. Caesar deployed his experienced pilae, the javelin throwers, against the threat of the large cavalry force of Pompey, telling them to thrust their javelins at the riders instead of throwing them. Pompey fled the battle while his troops were defeated under pressure. Caesar ransacked Pompey's camp, and took control of the remainder of Pompey's army.

Aftermath

Pompey fled from Pharsalus to Egypt, where he was assassinated on the order of Pharaoh Ptolemy XIII. The Battle of Pharsalus ended the wars of the First Triumvirate, and left Caesar 'supreme commander' of the Roman World. Caesar spent the next few years 'mopping up' remnants of the Senatorial Faction. After finally completing this task, he was assassinated in a conspiracy arranged by Marcus Junius Brutus and Gaius Cassius Longinus.

Trivia

The battle gives its name to
*Pharsalia, New York, U.S.
Pharsalia, a poem by Lucan

Further reading

*William E. Gwatkin, Jr., Some Reflections on the Battle of Pharsalus, Transactions and Proceedings of the American Philological Association, Vol. 87. (1956), pp. 109-124.