Complex sentence: The next year, in 1179, Kiyomori staged a coup d'etat forcing the resignation of his rivals from all government posts and subsequently banishing them, then filled the open government positions with his allies and relatives, and imprisoning the cloistered emperor Go-Shirakawa.
Split into simpler sentences: The next year, in 1179, Kiyomori staged a coup d'etat forcing the resignation of his rivals from all government posts and subsequently banishing them. He then filled the open government positions with his allies and relatives, and imprisoned the cloistered emperor Go-Shirakawa.