The siege of Alkmaar lasted from the 21st of August till the 8th of October 1573. Alkmaar was besieged by the Spanish army, led by Don Frederic, the son of the Duke of Alva. The siege ended when the order was issued that the dikes around Alkmaar were to be breached. This made it impossible for the Spaniards to continue the siege. Their withdrawal is now know as the delivery of Alkmaar. Alkmaar was one of the first cities from Holland to be liberated.