The Siege of Namur, 25 May–30 June 1692, was a major engagement of the Nine Years' War, and was part of the French grand plan (devised over the winter of 1691–92) to defeat the forces of the Grand Alliance and bring a swift conclusion to the war. Namur, sitting on the confluence of the Meuse and Sambre rivers, was a considerable fortress, and was a significant political and military asset. French forces, guided by Vauban, forced the town's surrender on 5 June, but the citadel, staunchly defended by Menno van Coehoorn, managed to hold on until 30 June before capitulating, bringing an end to the 36-day siege.