Deiotarus of Galatia (in Galatian and Greek Deiotaros, surnamed Philoromaios ("Friend of the Romans"); 42 BC, 41 BC or 40 BC) was a Chief Tetrarch of the Tolistobogii in western Galatia, Asia Minor, and a King of Galatia ("Gallo-Graecia"). He was considered one of the most adept of Celtic kings, ruling the three tribes of Celtic Galatia from his fortress in Blucium. The name Deiotarus is generally translated as Galatian Celtic "Divine-bull" (*deiuo-tauros; cf. Old Irish dia, Welsh duw, Old Welsh duiu, "God" and Old Irish tarb, Welsh tarw "bull", with Western Celtic metathesis of the cluster -uro- to -ruo-). Biography Deiotarus was a faithful ally of the Romans and became involved in the struggles between the Roman generals that led to the fall of the Republic from 44 BC. He changed sides and supported the triumvirs, keeping his kingdom until his death. He is first heard of at the beginning of the Third Mithridatic War, when he drove the troops of Mithridates VI of Pontus under Eumachus from Phrygia, and he was a witness when Mithridates VI saw his invasion of Phrygia stopped by the Romans, both in 75 BC or 74 BC. His most influential friend was Pompey. When settling the affairs of Asia after Mithridates VI failed in his invasion of Phrygia sometime between 60 BC and 65 BC, Pompey rewarded Deiotarus for his assistance against him with the title of King. Deiotarus increased his territory to include part of eastern Pontus, and the Roman Senate granted him Lesser Armenia and most of Galatia. On the outbreak of the civil war in 49 BC, Deiotarus naturally sided with his old patron and ally Pompey and the Optimates in their fight against Julius Caesar, who was defying the Senate. When Pompey was defeated at the Battle of Pharsalus in 48 BC, he escaped back to Asia-Minor. After Pharsalus Deiotarus faced execution, but was saved by switching sides and later by the advocacy of Cicero. During this time, Pharnaces, the son of Mithridates, had seized Lesser Armenia, and defeated Deiotarus' Galatian legions which were part of Domitius Calvinus' army in the Battle of Nicopolis. Fortunately for Deiotarus, Julius Caesar at that time (47 BC) arrived in Asia from Egypt, and was met by the tetrarch in the dress of a suppliant. Caesar pardoned him for having sided with Pompey, ordered him to resume his royal attire, and hastened against