The University Duisburg-Essen (German: Universität Duisburg-Essen) is a public university in Duisburg and Essen, North Rhine-Westphalia, Germany and a member of the new founded University Alliance Metropolis Ruhr. It was founded on January 1, 2003 as a merger of the Gerhard Mercator University of Duisburg and the University of Essen, both of which were established in 1972. Until 1994 the name of the Gerhard Mercator University was Comprehensive University of Duisburg. With its 12 departments and more than 30 thousand students, the University Duisburg-Essen ranks among the 10 largest German universities. Many international students study at the University Duisburg-Essen and give the cities of Duisburg and Essen an international atmosphere. Its origins date back to the 1555 decision of Duke Wilhelm V von Jülich-Kleve-Berg to create a university for the unified duchies at the Lower Rhine. To this end, it was necessary to obtain a permission of the emperor and the pope.