A member of the Byzantine high nobility and cousin of emperors Isaac II Angelos and Alexios III Angelos, Kamytzes served as a senior military commander in the Balkans, with the rank of "protostrator", from 1185/86 until 1199. For Isaac II he fought against the Norman invaders in 1185 and the uprising of Alexios Branas in 1186/87. Kamytzes twice campaigned against the Vlach–Bulgarian rebellion in the northern Balkans, as well as against Cuman raiders in the same region. In 1189, he clashed with the German contingent of the Third Crusade, under Frederick I Barbarossa, as they crossed Byzantine territory.