Complex sentence: Andronikos I Komnenos lived under the rule of Manuel I Komnenos, he was always faithful to the emperor, he however refused to take an oath of allegiance to the future king Béla III of Hungary, whom Manuel desired to become his successor.
Split into simpler sentences: Andronikos I Komnenos lived under the rule of Manuel I Komnenos. He was always faithful to the emperor, but he refused to take an oath of allegiance to the future king Béla III of Hungary, whom Manuel desired to become his successor.