The siege of Bergen op Zoom was a siege that took place during the Eighty Years' War and the Anglo–Spanish War between September 23 - November 13, 1588. The siege was between a besieged Anglo-Dutch force under Thomas Morgan and Peregrine Bertie and a Spanish besieging force under famed commander Alexander Farnese, the Duke of Parma. An English officer Grimstone claimed to be a disaffected Catholic, had set up a trap during which a large Spanish assault was then bloodily repulsed. An Anglo-Dutch relief column under the command Maurice of Orange soon after arrived and forced the Duke of Parma to retreat, thus ending the siege.