Complex sentence: He set sail in Enkhuizen, together with his uncle John, Duke of Beaumont, and landed near Stavoren and Laaxum but he was however ambushed and killed, in a battle known as the battle of Warns.
Split into simpler sentences: He set sail in Enkhuizen, together with his uncle John, Duke of Beaumont, and landed near Stavoren and Laaxum. He was, however, ambushed and killed, in a battle known as the Battle of Warns.