Marshal Boufflers began the investment on 15 March; the trenches were opened ten days later. In one of the most intense attacks of all King Louis’ wars, two batteries, each consisting of 12 mortars, bombarded the city in preparation for the assault; by 30 March, the French had fired 7,000 cannonballs and 3,000 mortar shells. Inevitably, at 17:00 on 8 April, the besieged inhabitants beat the chamade; conditions were settled, and the remaining men of the garrison marched out two days later.