a town of Germany, in the Prussian Rhine Province on the navigable Ruhr, 4 m. by rail E. of Essen, at the junction of the lines Duisburg-Dortmund and Vohwinkel-Hagen. Pop. (1905), 12,988. It contains a Gothic parish church (Roman Catholic), a high school and a Roman Catholic hospital. It has coal-mines, iron and steel works, and makes fireproof bricks. A Diet of the empire was held here in the year 938 by the emperor Otto I.