Tønsberg (pronounced [ˈtœ̂nsbær(ɡ)] ), historically Tunsberg, is a city in Tønsberg Municipality in Vestfold county, Norway. It is located about 102 kilometres (63 miles) south-southwest of the capital city of Oslo on the western coast of the Oslofjord near its mouth onto the Skagerrak. The city is the most populous metropolis in Vestfold county. Tønsberg also serves as the administrative centre for Vestfold county and the seat of the County Governor of Vestfold og Telemark.
Tønsberg is generally regarded as the oldest city in Norway, founded in the 9th century. Snorri Sturluson mentions the town in Harald Hårfagre's saga (written around 1220) before the battle at Hafrsfjord, which historians have traditionally dated to the year 872, therefore the town was in existence by 871 at the latest. This dating is again based on Are Frode's book, Íslendingabók. Using this information, Tønsberg celebrated its one-thousandth anniversary in 1871 and its 1100th anniversary in 1971. Archaeological findings confirm that there was a farm settlement in Tønsberg at the end of the 8th century, which likely developed into a town during the early 9th century.
