The castle had a curtain wall and was surrounded by a moat which had an inner diameter of about 50 meters and with a large, solid tower as an entrance gate. The castle was still the property of the Bishop of Roskilde until King Eric of Pomerania usurped the rights to the castle in 1417. The Hanseatic League attacked the castle and in the Bombardment of Copenhagen during the Dano-Hanseatic War (1426–1435). The attack was fought back by in 1428 by Queen Philippa, who led the defense from Copenhagen Castle.