History
| c.1000 AD | first settlement in the area of the present Waldhof |
| 1214 | founding of the town by Count Hermann IV of Ravensberg |
| after 1240 | construction of Sparrenburg Castle and development of the new town |
| 1293 | establishment of St.Marien seminary |
| 1346 | after the end of the House of Ravensberg, the county falls to the House of Jülich-Berg |
| C.14 | Bielefeld joins the Hanseatic League |
| 1452 | diversion of the river Luther to fill the town moat |
| 1511 | consecration of Franciscan monastery at Klosterplatz |
| 1511 | Bielefeld, with the county of Ravensberg, falls to the House of Kleve |
| 1520 | integration of old town and new town |
| c.1550 | fortification of Sparrenburg Castle completed |
| 1554 | the Reformation reaches Bielefeld |
| 1648 | end of the Thirty Year War. Bielefeld and the county of Ravensbergbecome part of Brandenburg |
| 1652 | establishment of the first Legge,a linen testing institution by the Great Elector |
| 1666 | discovery of a medicinal spring at Kesselbrink, giving Bielefeld spa town status for over 150 years |
| 1768 | merchants establish a modern bleaching works, Bielefeld's first joint stock company |
| 1775 | construction of barracks for the Bielefeld garrison under Frederick the Great, using facing stones from Sparrenburg Castle. After 1830 major crisis in the linen trade caused by cheap, machine-made yarns and cloths from abroad |
| 1847 | the new Cologne-Minden railway connects Bielefeld to the German and European rail network |
| 1851 | the Bozi brothers establish "Spinnerei Vorwärts", the first large mechanised spinning mill in the town |
| 1854 | founding of the "Ravensberger Spinnerei" spinning mill as a joint stock company under Hermann Delius |
| 1860 | the first metal industry company starts production, later to become the "Kochs Adler-Werke" |
| 1867 | establishment of the "Dürkopp-Werke" company |
| 1872 | Pastor Friedrich von Bodelschwingh becomes head of Bethel, a charitable institution founded in 1867 |
| 1879 | the town purchases the ruin of Sparrenburg Castle from the Prussian state for 8934.90 Marks. Rebuilding begins |
| 1891 | Dr. August Oetker takes over Aschoff's chemist's shop, here developing his well-known pre-packed baking powder |
| 1900 | inauguration of tram services in Bielefeld |
| 1904 | opening of the municipal theatre, construction of the town hall at Schillerplatz and of the post office at Herforder Straße |
| 1910 | construction of the main railway station |
| 1917 | official opening of the farmhouse museum at Ochsenheide |
| 1930 | Bielefeld becomes a city by incorporating parts of neighbouring communities |
| 1930 | opening of the "Rudolf Oetker-Halle" concert hall, famous for its excellent acoustics |
| 1933 | banning of unions and the Social Democrat "Volkswacht", dissolution of democratic political parties |
| 1938 | the synagogue is burnt down in the Third Reich's pogrom night |
| 1944 | heaviest air strike on Bielefeld on September 30. Large area of the town turns to rubble; more than 600 people die |
| 1945 | entry of American troops in April. The British take over the military administration in May |
| 1946 | Artur Ladebeck becomes the first democratically elected mayor |
| 1953 | official twinning with the English town of Rochdale |
| 1968 | the foundation stone is laid for Bielefeld University. The city art gallery is opened |
| 1968 | "Arminia Bielefeld" football club reach the First Division |
| 1973 | Northrhine-Westphalian boundary changes: the town of Bielefeld and its district are merged |
| 1974 | end of production at the Bielefeld site of Ravensberger Spinnerei |
| 1990 | opening of the civic hall |
| 1991 | official opening of the Stadtbahn tram network, running underground in the city centre |
| 1993 | opening of the Seidensticker Hall |
| 1994 | the History Museum is opened in the Ravensberger Spinnerei park |
| 1995 | official handing over of the arts and crafts collection Huelsmann in the former manager's mansion of the Ravensberger Spinnerei |