Dortmund is an independent city in North Rhine-Westphalia, Germany. It is in the middle part of the state and is considered the administrative, commercial and cultural centre of the eastern Ruhr area. Its population of 601,402 makes it the 8th largest city in Germany. Moreover, Dortmund is the largest city by area and population in the Ruhr Area, an urban area with some 5.1 million inhabitants which is the largest urban agglomeration in Germany.
Founded around 882, Dortmund became an Imperial Free City. Throughout the 13th to 14th centuries, it was the "chief city" of the Rhine, Westphalia, the Netherlands Circle of the Hanseatic League. After the Thirty Years' War the city was destroyed and decreased in significance until the onset of industrialization. The city then became one of Germany's most important coal, steel and beer centres. Dortmund consequently was one of the most heavily bombed cities in Germany during World War II. The devastating bombing raids of 12 March 1945 destroyed 98% of buildings in the inner city center. These bombing raids, with more than 1,110 aircraft, hold the record to a single target in World War II.