In the early Middle Ages it was a royal court of the Franks, first mentioned in writing in 883.
Duisburg is a result of numerous incorporations of surrounding towns and smaller cities. It is the fifteenth-largest city in Germany and the fifth-largest city in North Rhine-Westphalia with 486,855 residents at the end of 2013. It is the central city of the Rhine-Ruhr metropolitan area. The city is renowned for its steel industry. All blast furnaces in the Ruhr are now located in Duisburg. In 2000, 49% of all hot metal and 34.4% of all pig iron in Germany was produced here. It also has a large brewery, König. The University of Duisburg-Essen, with 39,000 students, ranks among the ten largest German universities.