Illyricum had seen some fighting during the Great Roman Civil War between Julius Caesar and the forces of the Senate led by Pompey several decades earlier. The Romans who lived in some of the coastal towns supported Caesar, while the native peoples largely supported Pompey. Quintus Cornificius, a Caesarian, repulsed Quintus Octavius, a Pompeian. The Dalmatians routed Aulus Gabinius, a Caesarian who had been ordered by Caesar to join Cornificius in Illyricum. The Dalmatians later asked Caesar for pardon. Caesar demanded a tribute and hostages as compensation, which was standard practice, and sent Publius Vatinius with three legions to enforce this. After Caesar was assassinated in 44 BC, the Dalmatians ignored these demands and routed five of Vatinius' cohorts. With the disruptions caused by further Roman civil wars in the years following, Dalmatian piracy in the Adriatic Sea became a problem again.