The monastery was frequently damaged during sieges due to its elevated location near the western city wall. The monastery suffered particularly during the Eighty Years' War. During the Siege of Maastricht (1579) many Crutched Friars died; those that survived perished during the ensuing plague epidemic. For a while the monastery remained uninhabited. In 1581 prior Hubertus of Stavelot sold some of the Crosiers' possessions in order to pay for the repair of the monastery buildings (including the partial renewal of the church's vaults). In 1582 the books that had been shipped to Aachen for safety, returned to Maastricht. After this, the monastery would not reach the same level of prosperity that it had enjoyed before. Where it had previously 25 or more friars, in 1615 it had only 9, and throughout the 17th and 18th century it would never exceed 15.