In 1014 he was among the Byzantine commanders during the battle of Kleidion. The Bulgarians under Emperor Samuil had built a thick wooden wall to prevent further enemy invasions. When the Byzantines were desperate after the heavy casualties they suffered in the futile attempts to assault the wall, Xiphias and his troops managed to find a path which lead them into Bulgarians' rear. As a result the Byzantines achieved a major victory which brought the end of the First Bulgarian Empire four years later. In 1022, he allied himself with Nicephorus Phocas and revolted against Basil II. The rebellion quickly proved abortive as jealous Xiphias had Phocas assassinated and then was forced to surrender to the emperor. He was tonsured, and banished as his estate was confiscated.