The Battle of Pharsalus was a decisive battle of Caesar's Civil War. On 9 August 48 BC at Pharsalus in central Greece, Gaius Julius Caesar and his allies formed up opposite the army of the republic under the command of Gnaeus Pompeius Magnus ("Pompey the Great"). Pompey had the backing of a majority of the senators, of whom many were optimates, and his army significantly outnumbered the veteran Caesarian legions.