Verdun (vĕrdŭnˈ, Fr. vĕrdöNˈ) [key], town (1990 pop. 23,427), Meuse dept., NE France, in Lorraine, on the Meuse River. A strategic transportation center, Verdun has varied industries and is situated in an agricultural region. The town was a prosperous commercial center in Roman times and also during the Carolingian period in the 800s. An episcopal see since the 4th cent., Verdun, with its surrounding area, was one of the three bishoprics (with Metz and Toul) seized (1552) by Henry II of France from the Holy Roman Empire. The town itself was a free imperial city before it passed to France. The Peace of Westphalia (1648), ending the Thirty Years War, confirmed Verdun in French possession. Fortified by Sébastien Vauban during the reign of Louis XIV, Verdun thereafter became important strategically. After 1871 the town became the principal French fortress facing Germany and was surrounded by a ring of defenses. The longest battle of World War I was fought at Verdun in 1916 (see Verdun, battle of). In 1918 the Americans and French were victorious in the Verdun sector and at Saint-Mihiel. Almost totally destroyed, Verdun was rebuilt after the war. The town and the battlefield of Verdun, with their huge military cemeteries and numerous impressive monuments, form a national sanctuary. Other points of interest are the cathedral (11th–12th cent.) and the town hall (17th cent.), which is now a war museum.