A descendant of the noble Katakalon and Euphorbenos families, Constantine is first mentioned in the sources when he commanded the Chomatenoi corps and the Turkish contingent of Alexios Komnenos' army in the Battle of Kalavrye in 1078. He appears again in the lists of the Synod of Blachernae in 1094, bearing the title of protokouropalates. In the next year, he took part in Alexios' campaign against the Cumans. Alexios sent him to attack the Cumans while they were crossing the Zygos pass, but the latter, guided by local Vlachs, managed to cross the pass sooner and seize the town of Goloe. Katakalon nevertheless attacked the Cuman foraging parties and managed to capture about a hundred prisoners, for which he was promoted to nobelissimos. He was next dispatched to assist the city of Adrianopl