The Flemish attacked Hainaut and Zeeland supported by the dissatisfied population there.
Guy of Namur defeated John's son, William, in a battle on the island of Duiveland.
Guy of Namur and Duke John II of Brabant conquered most of Utrecht, Holland, and Zeeland.
Guy of Namur was finally defeated in 1304 by the fleet of Holland and France at the naval Battle of Zierikzee.
In 1270, John married Philippa,[5] daughter of Count Henry V of Luxembourg and Margaret of Bar.