Complex sentence: In 1183 the king lost his eldest son, Henry the Young King of England and in 1185 his third son, Geoffrey, Duke of Brittany, was trampled to death in a tournament near Paris.
Split into simpler sentences: In 1183 the king lost his eldest son, Henry the Young King of England. In 1185 his third son, Geoffrey, Duke of Brittany, was trampled to death in a tournament near Paris.