Lasting peace did not, however, return to the land and several times epidemics struck the town. In 1580 it was almost completely depopulated by the plague. During the Spanish-Dutch War in 1607, Dutch troops took the town and plundered it. After Erkelenz had been unsuccessfully besieged in 1610 during the Jülich-Cleves War of Succession, the army of the French king, Louis XIV, allied with the troops of the Archbishop of Cologne, was finally in a position to take the town on the evening of 9 May 1674. This attack which took place during the French-Dutch War only succeeded on the fourth assault using the newly invented cannons, when two of the four gates fell. On that day, the town ceased to be a fortification. The attackers are reported to have lost 400 dead, the defenders just six. The invaders forced the townsfolk to breach the walls and blew up the Bellinghoven and Oerath gates, both of which blocked free passage to the Netherlands.