Kaiserslautern (kĪˌzərslouˈtərn) [key], city (1994 pop. 102,370), Rhineland-Palatinate, W Germany, on the Lauter River. It is a commercial, industrial, and cultural center, and a center for banking and rail shipment. There are textile mills and machine and automobile factories. Charlemagne built a castle in Kaiserslautern that was later enlarged (1153–58) by Emperor Frederick I (Barbarossa); some ruins of the castle remain today. The city was repeatedly devastated by warring armies, notably by the Spanish (1635) in the Thirty Years War. During the French Revolutionary Wars the Prussians defeated (1793) the French there. Kaiserslautern has a noted early Gothic collegiate church (13th–14th cent.) and an art gallery. Formerly the seat of part of the Univ. of Trier and Kaiserslautern (founded 1970), the Kaiserslautern campus became independent in 1975.