Complex sentence: Under Constantine I Tikh the country lost northern and central Macedonia to Byzantium as well as Severin Banat to Hungary and the crisis drove to peasant war, raised by the swineherd Ivailo, who managed to sit on the Bulgarian throne from 1277 to 1280.
Split into simpler sentences: Under Constantine I Tikh the country lost northern and central Macedonia to Byzantium as well as Severin Banat to Hungary. The crisis led to a peasant war, raised by the swineherd Ivailo, who managed to sit on the Bulgarian throne from 1277 to 1280.