Saarlouis (zärˌlōˈē) [key], Fr. Sarrelouis, city (1994 pop. 38,347), Saarland, SW Germany, on the Saar River near the French border. It is a commercial and industrial center. Manufactures include steel, furniture, tobacco products, and bells. Coal is mined in the area. Founded (1680) by Louis XIV, for whom it was named, Saarlouis was fortified (1680–85) by Vauban and became a major French frontier fortress. It was awarded (1815) to Prussia at the Congress of Vienna. As part of the Saar Territory (see Saarland), it was administered by France from 1919 to 1935 and from 1945 to 1957. From 1935 to 1945 the city was known as Saarlautern. Marshal Ney of France was born there in 1769.