h the Zulu was one of the least significant of the chiefdoms absorbed during the course of Mthethwa expansion, its status changed markedly when Shaka usurped the Zulu chieftainship from his brother in 1816. One year after Dingiswayo's death Shaka's army defeated Zwide's, and Zulu expansionism proceeded apace. By the time of his assassination in 1828, Shaka had forged a kingdom bounded on the north by the Phongolo river, on the south by the Thukela and in the west by the Drakensberg. He evidently succeeded as a state-builder by perfecting Dingiswayo's military innovations: replacement of the long throwing spear with the short stabbing assegai; use of the winged battle formation; creation of female age-regiments; and establishment of a hierarchy of civil and political officials subordinate to the king.