The Siege of Alkmaar (1573) was a turning point in the Eighty Years' War. The burghers of the Dutch city of Alkmaar held off the Spanish (who had set up their camp in Oudorp) between August 21 and October 8, 1573, with boiling tar and burning branches from their renewed city walls. On September 23, William the Silent followed up on a request by Cabeliau dating from the beginning of the siege and ordered the dikes surrounding Alkmaar to be breached, thereby flooding the polders in which the Spanish troops were camped. This forced the Spanish commander, Don Fadrique, the son of the hated Alva himself, to retreat and the last Spanish soldiers left on October 8