Defeating the Vocates and Tarusates proved a tougher task. Having allied with the rebel Roman general Quintus Sertorius during his uprising in 70 BCE, these tribes were well versed in Roman combat, and had learned guerilla tactics from the war. They avoided frontal battle and harassed supply lines and the marching Romans. Crassus realized he would have to force battle and located the Gallic encampment of some 50,000. However, they had only fortified the front of the camp, and Crassus simply circled it and attacked the rear. Taken by surprise, the Gauls attempted to flee. However, Crassus' cavalry pursued them. According to Crassus, only 12,000 survived the overwhelming Roman victory. The tribes surrendered, and Rome now controlled most of southwest Gaul.