 A year later, Augusto dos Santos began serving as the Portuguese Army Chief of Staff (Chefes do Estado-Maior do Exército), a post he held until 1972.He was retired at the time of the military coup in Lisbon on 25 April 1974, which overthrew the Portuguese government headed by Marcelo Caetano and would put to an end the Portuguese Colonial War (1961-1974) shortly after.He refused to participate in the revolution even though he was asked to participate in the revolutionary government.