Originally a Saxon settlement where Charlemagne established a bishopric in 785, the city was chartered in 1171 and was a Hanseatic League member known especially for its “Osnaburg” linen. The city accepted the Reformation in 1543 and remains predominantly Protestant. The Peace of Westphalia, signed there in 1648, stipulated that the bishopric was to be held alternately by Roman Catholics and Protestants. Ernest Augustus, elector of Hanover and the father of George I of England, was the first Protestant bishop. The see was secularized and given to Hanover in 1803, but it was reestablished as a Roman Catholic bishopric in 1858.
Osnabrück is a major rail junction with factories processing copper and producing machinery, motor-vehicle equipment, chemicals, textiles, synthetic materials, and paper. The city suffered widespread destruction in World War II, but several historic buildings survived, including the palace of the elector bishops (1667–90), the city hall (1487–1512) with its peace hall (Friedenssaal), and the Gothic church of St. Mary (1280–1324). Other medieval buildings include the 13th-century Romanesque cathedral and St. John’s and St. Katherine’s churches. There are town houses dating from the 13th–19th centuries, one of which was the birthplace of the writer and statesman Justus Möser (1720–94). The city is the seat of the University of Osnabrück (founded 1973). Osnabrück features a municipal zoo, a planetarium, and a museum of cultural history. In the vicinity are several moated castles (e.g., Schloss Gesmold) and spas (e.g., the saline springs of Melle). Pop. (2003 est.) 165,517.