Friedrichshafen (frēˈdrĭkhs-häˌfən) [key], city (1994 pop. 56,050), Baden-Württemberg, S Germany, a port on Lake Constance. Industries include ship and railroad car repair, leatherworking, and the manufacture of cars and textiles. Friedrichshafen was formed in 1811 by the union of the towns of Buchhorn (founded by the 9th cent.) and Hafen (founded in the mid-11th cent.). In 1824 it became the summer residence of the kings of Württemberg. As the site of the Zeppelin aircraft works, Friedrichshafen suffered heavy damage in World War II. Of interest are the baroque ducal castle (originally a Benedictine abbey) and its church (both built in the late 17th cent.).