Hagen is the 41st-largest city in Germany, located in the federal state of North Rhine-Westphalia. It is located on the south eastern edge of the Ruhr area, 15 km south of Dortmund, where the rivers Lenne and Volme (met by the river Ennepe) meet the river Ruhr. As of 31 December 2010 the population was 188,529. The city is home to the FernUniversität Hagen, which is the only state funded distance education university in Germany. Counting more than 67,000 students (March 2010), it is the largest university in Germany.HistoryHagen was first mentioned ca. 1200, presumably the name of a farm at the junction of the Volme and the Ennepe. After the conquest of Burg Volmarstein in 1324, Hagen passed to the County of Mark. In 1614 it was awarded to the Margraviate of Brandenburg according to the Treaty of Xanten. In 1701 it became part of the Kingdom of Prussia.After the defeat of Prussia in the Fourth Coalition, Hagen was incorporated into the Grand Duchy of Berg from 1807–13. In 1815 it became part of the new Prussian Province of Westphalia.