Complex sentence: He joined his regiment in India and from 29 April 1879 he was adjutant of his battalion, and, having been promoted to captain on 29 May 1882, he accompanied his battalion to the Sudan in 1884 in the expedition under Sir Gerald Graham VC.
Split into simpler sentences: He joined his regiment in India and from 29 April 1879 he became adjutant of his battalion. Promoted to captain on 29 May 1882, he accompanied his battalion to the Sudan in 1884 as part of the expedition under Sir Gerald Graham VC.