Lentulus recruited two legions in the province of Asia for Pompeius - a decree of his in July 49 BC exempted the Jews of Asia Minor from military service. He was with Pompeius, as Proconsul, in his defeat at the Battle of Pharsalus on 9 August 48 BC, where he commanded the Pompeian left wing. On his flight from the battlefield Lentulus was denied refuge in Antioch and instead followed Pompeius to Egypt. He was taken prisoner on 4 September by the order of King Ptolemy XIII and executed whilst in prison.