Bielefeld (ˈbiːləfɛlt) is a city in the Ostwestfalen-Lippe Region in the north-east of North Rhine-Westphalia, Germany. With a population of 341,755, it is also the most populous city in the administrative region (Regierungsbezirk) of Detmold and the 18th largest city in Germany.
The historical centre of the city is situated north of the Teutoburg Forest line of hills, but modern Bielefeld also incorporates boroughs on the opposite side and on the hills. The city is situated on the Hermannsweg, a hiking trail which runs for 156 km along the length of the Teutoburg Forest.
Bielefeld is home to a significant number of internationally operating companies, including Dr. Oetker, Gildemeister and Schüco. It has a university and several technical colleges (Fachhochschulen). Bielefeld is also famous for the Bethel Institution, and for the Bielefeld conspiracy, which satirises conspiracy theories by claiming that Bielefeld does not exist. This concept has been used in the town's marketing and alluded to by Chancellor Angela Merkel.
Founded in 1214 by Count Hermann IV of Ravensberg to guard a pass crossing the Teutoburg Forest, Bielefeld was the "city of linen" as a minor member of the Hanseatic League, known for bleachfields into the 19th Century. Bielefeld was part of the Kingdom of Westphalia when it was created in 1807. In 1815 it was incorporated into the Kingdom of Prussia following the defeat of France and the Congress of Vienna.
After the Cologne-Minden railway opened in 1849, the Bozi brothers constructed the first large mechanised spinning mill in 1851. The Ravensberg Spinning Mill was built from 1854 to 1857, and metal works began to open in the 1860s.
Founded in 1867 as a Bielefeld sewing machine repair company, Dürkoppwerke AG employed 1,665 people in 1892; it used Waffenamt code "WaA547" from 1938 to 1939 as the Dürkopp-Werke, and merged with other Bielefeld companies to form Dürkopp Adler AG in 1990.
Between 1904 and 1930, Bielefeld grew, opening a rebuilt railway station, a municipal theatre, and finally, the Rudolf-Oetker-Halle concert hall, renowned for its excellent acoustics.