The defeated Spanish garrison leaving Den Bosch, 17 September 1629, by Pauwels van Hillegaert, c. 1630. Soldiers, Catholic priests and a long line of wagons are leaving Den Bosch. Some have already passed the town's outer defences. The siege lasted four months before the Spaniards were forced to open the gates to Frederick Henry. By capturing Den Bosch - strategically located in the south of the Republic - the Dutch guaranteed the security of their state. For the Catholics of Brabant, however, it represented the start of a period of repression.