The Syrian legion then invested Jerusalem, but for uncertain reasons and despite initial gains withdrew back towards the coast, where it was ambushed and defeated by Judean rebels at the Battle of Beth Horon, a result that shocked the Imperial leadership. The defeat of the Romans in Beth Horon is considered one of the worst military defeats of the Roman Empire by a rebel province throughout its history. Some 6,000 Roman troops were killed and many more wounded in the battle, with Legio XII "Fulminata" losing its "aquila", as Gallus abandoned his troops in disarray, fleeing to Syria. Victorious Judean militias included Sadducee and Pharisee factions, with a major role also played by the peasantry led by Simon Bar Giora, Zealot faction led by Eleazar ben Simon, as well as elements of the Sicarii.