Mal volunteered for the Independents army during the Unification War against the Alliance, gaining the rank of sergeant during that time. His loyal second-in-command Zoe was by his side for most of the war, surviving many dangerous conflicts with him. The show mentions three such battles, including the Battle of Du-Khang in 2510 (featured in "The Message") and a long winter campaign in New Kashmir (as told by Zoe in "War Stories") where he commanded a platoon. Mal was also involved in the ground campaign during the Battle of Sturges (as seen in the comic book Serenity: Those Left Behind), which according to Badger was the "bloodiest and shortest battle in all the war", although Mal considers it a distant second. Mal fought in many more battles, but the turning point for him and the Independents came with their physical and emotional defeat at the Battle of Serenity Valley on the planet Hera. On-screen information from the film Serenity suggests that Mal was given a brevet promotion to Captain during the Battle of Serenity Valley to take command of the ever-increasing number of Independent troops who were losing their officers at the hands of the Alliance. This might explain why, in one of the deleted scenes from the Firefly pilot, Mal is described as having commanded at least 2000 men. On-screen information in Serenity shows him to have been attached to the 57th Overlanders Brigade; in the series pilot, Badger calls it the "Balls and Bayonets Brigade", though it is unclear whether that was a disparaging nickname coined by Badger himself or the actual unit sobriquet.