In 1961, guided by António de Oliveira Salazar, he offered himself for voluntary service in Portuguese colonies of West Africa. Between 1961 and 1963, he held the command of the 345th Cavalry Battalion in Portuguese Angola, distinguishing himself and his unit. At the end of his tenure, he was appointed for, and served as, the Governor and Commander-in-Chief of the Armed Forces of the Portuguese Guinea from 1968, and again in 1972, during the period of the Overseas War, where his administration favoured a policy of respect for ethnic Guineans and the traditional authorities. At the same time, he continued to practice a range of initiatives in the War, from clandestine meetings (he met secretly with the President of Senegal, Léopold Sédar Senghor, at one point) to armed incursions to neighbouring states (such as Operation Green Sea, which saw the assault by Portuguese Army Commandos into Conakry, Guinea).