According to Beevor, 12,000 Portuguese participated. Othen claims the number was closer to 8,000. A Portuguese Military Observation Mission with members drawn from all three branches of the Portuguese military was present in Spain from 1937 onwards with the dual objectives of protecting the interests of Portuguese foreign volunteers and collating information on the lessons learned in the civil war. Although the Mission officially had a non-combatant role its airforce contingent took part in combat missions.