Augusto José Ramón Pinochet Ugarte, more commonly known as Augusto Pinochet ( or ; 25 November 1915 – 10 December 2006), was  dictator of Chile between 1973 and 1990 and Commander-in-Chief of the Chilean Army from 1973 to 1998. He was also president of the Government Junta of Chile between 1973 and 1981. Pinochet assumed power in Chile following a United States-backed coup d'état on 11 September 1973 that overthrew the elected socialist Unidad Popular government of President Salvador Allende and ended civilian rule. Several academics have stated that the support of the United States was crucial to the coup and the consolidation of power afterward. Pinochet had been promoted to Commander-in-Chief of the Army by Allende on 23 August 1973, having been its General Chief of Staff since early 1972. In December 1974, the ruling military junta appointed Pinochet President of Chile by joint decree, although without the support of one of the coup's instigators, Air Force General Gustavo Leigh.