Ruhr (river)

Ruhr (river), name of a river and a region of Germany. The Ruhr is a tributary of the River Rhine, rising in the west-central part of Germany, in the state of North Rhine-Westphalia. From its source in a mountainous region, the Ruhr flows generally west for 235 km (146 mi) and enters the Rhine at Duisburg. The course of the stream, which is navigable from its mouth to Witten (about one fifth of its total length), is extremely winding. Neighbouring canals carry most of the traffic of the Ruhr.

The Ruhr River Basin and adjacent areas, usually regarded as comprising the region that extends east from the Rhine between Wesel and Düsseldorf, is one of the most intensely developed industrial regions in the world. Immense deposits of bituminous coal are in the Ruhr valley, and the district is traversed by extensive networks of railway lines and inland waterways, with direct access, along the Rhine, to the Atlantic Ocean. A large proportion of the iron and steel, machinery and other metal products, chemicals, and textiles manufactured in Germany are produced in the Ruhr region. The primary industrial cities of the district are Essen, Düsseldorf, and Dortmund. Among other leading cities in the Ruhr district are Duisburg, Oberhausen, Gelsenkirchen, Bochum, and Wuppertal.

The Ruhr region has been settled since Paleolithic times, but the large-scale development of coal mining and heavy industry dates from the second half of the 19th century. Because of its productive capacity, the Ruhr was the core of the German war effort during World Wars I and II. France and Belgium occupied the region from 1923 to 1925. At the end of World War II about one third of the region's industrial facilities had been destroyed by Allied bombing. After the war, limitations were placed on the output of industrial production. The Ruhr was under the control of an international body from 1949 until 1952. In that year the European Coal and Steel Community was formed, and all restrictions on industrial output were abandoned. Today the Ruhr region is the most densely populated area of the country.