Count Dirk II built a fortress near Vlaardingen, which later was the site of a battle between his grandson Dirk III and an Imperial army under Godfrey II, Duke of Lower Lorraine.
Comte Dirk II membangun sebuah benteng di dekat Vlaardingen, yang kemudian adalah situs pertempuran di antara cucunya Dirk III dan pasukan kerajaan di bawah pimpinan Godfried II dari Lorraine.