Gallus was proconsul of Syria from 63 or 65. He marched into Judea with a force of over 30,000 men in September 66 in an attempt to restore order at the outset of the First Jewish–Roman War. As assembled at Antioch, Gallus' army comprised Legio XII Fulminata, detachments from the three other legions based in Syria, six cohorts of auxiliary infantry and four alae of cavalry.