Its foundation date is unknown. Rendsburg was first mentioned in 1199. An old form of its name was Reynoldsburgh: see this map. It became a part of Holstein in the 13th century, but was transferred to Schleswig in 1460. Many times the town passed from Danish to German control and vice versa. In the German-Danish War in 1864 Rendsburg was finally seized by Kingdom of Prussia and Austria. After 1866 the town was annexed by the Kingdom of Prussia. Since that time it has remained German.
Close view of transporter bridge
Its importance rose in 1895, when the Kiel Canal was finished. Although situated inland, Rendsburg became a seaport and a dockyard. The most prominent structure in town, a railway bridge made of steel, 2500 m in length and 41 m in height, was constructed in 1913. Mounted on the railway bridge, the Kiel Canal is also traversed by a transporter bridge, one of only twenty ever built. The German Army's Air Defence School is located in Rendsburg.