The oldest part of the city is built on the site of the ancient Roman city of Aelium Cetium that existed between the 2nd and the 4th century. In the year 799, it was called Treisma. Sankt Pölten didn't became a town in 1050 and officially became a city in 1159. Until 1494 Sankt Pölten was part of the diocese of Passau, and then became the property of the state. A Benedictine monastery was founded in 771. In 1081 it hosted the Augustinian Chorherren and in 1784 their Kollegiatsstift closed. Since 1785, this building has hosted the cathedra of Sankt Pölten. The city replaced Vienna as the capital of Lower Austria with a resolution by the Lower Austrian parliament on 10 July 1986. The Lower Austrian government has been hosted in Sankt Pölten since 1997.
The name Sankt Pölten is derived from Hippolytus of Rome. The city was renamed to Sankt Hippolyt, then Sankt Polyt and finally Sankt Pölten
