Complex sentence: It became a Byzantine possession during the early Middle Ages, but Byzantine rule was slight; according to Theophanes and others, Chersonesos was the residence of a Khazar tudun in the late 600s.
Split into simpler sentences: It became a Byzantine possession during the early Middle Ages, but Byzantine rule was slight. According to Theophanes and others, Chersonesos was the residence of a Khazar tudun in the late 600s.