Battle of Dyrrhachium (48 BC) - Prelude

Prelude

By the end of Julius Caesar's first year as consul he had accumulated a large list of lawsuits. Roman law gave government officials immunity from prosecution but only during their term of office. Once he became a private citizen Caesar knew he would be vulnerable and instead managed to obtain a proconsul position over the territories of Cisalpine Gaul and Illyricum, with the later addition of Transalpine Gaul. When his five years as proconsul ended Caesar assisted his allies Crassus and Pompey in being elected consuls and his pro-consulship was extended for a further five years. At the end of his term as Governor, having now met the condition on a minimum of ten years between elections as consul, the Senate ordered he resign command of his army. Caesar replied that he would agree to resign his military command if Pompey followed suit. Offended, the Senate demanded he immediately disband his army, or be declared an enemy of the people. In 50 BC, at his Proconsular term’s expiry, the Senate forbade Caesar's standing for election in absentia for a second consulship and because of this, Caesar thought he would be prosecuted and rendered politically marginal if he entered Rome without consular immunity or his army. Caesar responded by marching on Rome and he forced the unprepared Pompey and his allies to flee to Greece, starting the Great Roman Civil War.

Caesar did not immediately give chase to Greece and instead consolidated power in Rome and Italy. He had other problems as well, Pompey had left him with no ships to cross the Adriatic and Spain had begun to mobilize against Caesar. After gathering the remainder of his forces from Transalpine Gaul he marched into Spain and subdued enough of the country that it wouldn't intervene during his campaign against Pompey. He then turned his full attention to Pompey. Having only built half the needed ships Caesar grew impatient and decided to gamble on sending half his army across, and to then have the ships travel back to Rome and transport the remainder. Travel across the Adriatic Sea to Greece would ordinarily be difficult, but was made more so given that it was winter and the sea was treacherous. In addition Pompey's fleet, commanded by Caesar's former junior consul Marcus Calpurnius Bibulus, lay between Caesar and Greece. As it was winter Bibulus was unprepared and Caesar was able to sail through the blockade easily and form a beachhead at Epirus with the first half of his army. Bibulus however was able to block Caesar's attempt to sail his ships back to Italy, burning most of them. Bibulus died shortly after and command fell to Lucius Scribonius Libo.

Caesar's blunder had put him in the worst possible position any army could find itself in. His army had no way to resupply from Rome due to the naval blockade, he couldn't resupply locally as Greece was pro-Pompey and closed their gates to Caesar, and his army was only at half strength. So dire was his situation that he made several attempts to discuss peace with Pompey but was refused at every channel. Realizing he was going to have to fight his way out, he attempted another winter blockade run back to Italy to lead his remaining forces to Greece. His luck was not with him and the rough seas and storms forced him back. However, his Master of the Horse Marc Antony fired up his troops and after several attempts broke Libo's blockade and managed to make it north of Caesar's position. It was now a race against time as both Caesar and Pompey rushed to meet Antony. Although Pompey reached Antony first Caesar was right on his heels and Pompey prudently moved his forces to Dyrrachium to prevent becoming caught between the two forces.