With a population of , inhabitants, [ 3 ] it is the largest city by area and population of the Ruhr as well as the largest city of Westphalia. Dortmund is the second-largest city in the Low German dialect area, after Hamburg. Founded around , [ 4 ] Dortmund became an Imperial Free City. Throughout the 13th to 14th centuries, it was the "chief city" of the Rhine, Westphalia, and the Netherlands Circle of the Hanseatic League.
During 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; as a consequence, it was one of the most heavily bombed cities in Germany during World War II.
The raids, with more than 1, aircraft, were the largest for a single target in World War II. Since the collapse of its century-long steel and coal industries, the region has adapted and shifted to high-technology biomedical technology , micro systems technology , and also services.
Other key sectors include retail , [ 7 ] leisure and the visitor economy, [ 8 ] creative industries , [ 9 ] and logistics. Dortmund is home to many cultural and educational institutions. It is the location of the Technical University of Dortmund , Dortmund University of Applied Sciences and Arts , the International School of Management , and other educational, cultural and administrative facilities, with over 49, students.
Nearly half the municipal territory consists of waterways, woodland, agriculture, and green spaces with spacious parks such as Westfalenpark and Rombergpark.
