Sometime before 2222 the Pralor became involved in a war with the Cravic. Both sides constructed similar robotic "automated personnel units" to fight this war. When the Pralor and the Cravic eventually declared a truce and attempted to deactivated their respective APU's both races were destroyed by the robots, who saw their builders as their new enemies. The Pralor and Cravic robots continued the hostilities into the late 24th century.