Cicero, as he was in defense of the senate and Republican tradition, had in 50 BCE chosen to favor Pompey when the struggle between Pompey and Julius Caesar grew more intense, but at the same time he had prudently avoided openly alienating Caesar.

Cicero flees Rome in 49 BCE when Caesar invades Italy.

Caesar, seeking the legitimacy an endorsement by a senior senator would provide, has courted Cicero's favor, but even so Cicero slips out of Italy and travels to Dyrrachium (Epidamnos), Illyria, where Pompey's staff is situated.

Cassius Longinus, returning in 50 to Rome from Syria after a two-year stint as proquaestor, had been elected tribune of the Plebs for 49 BCE, and has thrown in his lot with the Optimates, although his brother Lucius Cassius supports Caesar.

Cassius had left Italy shortly after Caesar crossed the Rubicon.

Meeting Pompey in Greece, Cassius has been appointed to command part of his fleet.