Osnabrück is a city in Lower Saxony, Germany, some 100 kilometres (62 mi) NNE of Dortmund, 50 km (31 miles) NE of Münster, and some 130 km (81 miles) due west of Hanover. It lies in a valley penned between the Wiehen Hills and the northern tip of the Teutoburg Forest. As of December 31, 2012, its population was 154,513, making it the fourth-largest city in Lower Saxony. Historically, culturally as well as linguistically, Osnabrück belongs to the region of Westphalia.NameThe origin of the name Osnabrück is disputed. The suffix -brück suggests a bridge over or to something (from German Brücke = bridge) but the prefix Osna- is explained in at least two different ways: the traditional explanation is that today's name is a corruption of Ochsenbrücke (meaning "ox bridge") but others say that it is derived from the name of the Hase River which again is argued to be derived from Asen (Æsir), giving Osnabrück the meaning "bridge to the gods". The pronunciation of the city's name can also serve as a means of telling if one is a native of Osnabrück or a visitor: most people from Osnabrück stress the last syllable while most people from elsewhere stress the first one. The city gave name to the textile fabric of osnaburg (note: "-burg" means castle and, in names, town).HistoryMedievalOsnabrück developed as a marketplace next to the bishop's see founded by Charlemagne, king of the Franks, in 780. Some time before 803, the city became seat of the Prince-Bishopric of Osnabrück. Although the precise date is uncertain, it is likely that Osnabrück is the oldest bishopric in Lower Saxony.