Native African troops, although widely deployed were initially employed in subordinate roles as enlisted troops or noncommissioned officers. Portuguese colonial administrators were handicapped by their policies in education, which largely barred indigenous Africans from adequate education until well after the outbreak of the insurgency. With illiteracy rates approaching 99 per cent and almost no African enrollment in secondary schools, few African candidates could qualify for Portugal's officer candidate programs; most African officers obtained their commission as the result of individual competence and valour on the battlefield. As the war went on, an increasing number of native Africans served as noncommissioned or commissioned officers by the 1970s, including such officers as Captain (later Lt. Colonel) Marcelino da Mata, a Portuguese citizen born of native Guinean parents who rose to command from a first sergeant in a road engineering unit to a commander in the elite all-African "Comandos Africanos", where he eventually became one of the most-decorated soldiers in the Portuguese Army. Many native Angolans rose to positions of command, though of junior rank.