Châlons-en-Champagne (shälôN´-zäN-shäNpän´yə), formerly Châlons-sur-Marne (shälôN´-sür-märn), city (1990 pop. 51,533), capital of Marne dept., NE France, in Champagne, on the Marne River. It is a commercial and industrial center. Among its manufactures are electrodes, paper, hosiery, foundry products, and musical and precision instruments. There, in 451, the Huns under Attila were defeated by Actius. Although badly damaged in both World Wars, it still retains its cathedral (13th–17th cent.) and many remarkable Gothic churches. An arts and crafts school is there.