William was the eldest son of the Brunswick duke Henry the Mild from his first marriage with Sophia, daughter of the Griffin duke Wartislaw IV of Pomerania. ️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️<unk>️ William turned out to be an energetic ruler; he soon entered into numerous feuds with neighboring princes such as the Archbishop of Bremen and the Bishop of Hildesheim, and supported the Counts of Schauenburg and Holstein in their fight against King Eric of Denmark. <unk> <unk> <unk> <unk>
1421 Battle of Brüx.