The first time the town was mentioned by a contemporary writer was in 1130. According to Snorri Sturluson, T�nsberg was founded before the Battle of Hafrsfjord, which, according to Snorri, took place in 871. What year the battle took place is disputed, however, and most current historians believe the battle took place closer to 900. However, if the battle did in fact take place in 871, this would make T�nsberg the oldest present Scandinavian city. It was based upon this that the city's 1000 years jubilee was celebrated in 1871, and 1100 years jubilee in 1971. The archaeological excavations conducted in 1987-88 underneath the monastery ruins revealed several Viking graves which have served to confirm the earlier age of the original settlement.
The king or his ombudsman resided in the old Royal Court at S�heimr, today the Jarlsberg Estate (Jarlsberg Hovedg�rd), and on the farm Haugar, (from the Old Norseword haugr meaning hill or burial mound), which can be assumed to have been T�nsberg's birthplace. Haugar became the seat for Haugathing, the Thing for Vestfold and Norway's second most important place for the proclamation of kings. The site had probably been named after two Viking Era mounds, which tradition links to two sons of King Harald I, Olaf Haraldsson Geirstadalf, who was king in Vestfold, and his half-brother, Sigr�d Haraldsson, king of Trondheim. Both are presumed to have fallen in battle at Haugar against their half-brother Eric Bloodaxe and to have been buried on the same spot.
Slottsfjellet (English: Castle Mountain), north of the city centre, made for a near impregnable natural fortress. During the civil war era of the 12th century, it was fortified by theBaglers. The Birkebeiners besieged it for 20 weeks in the winter of 1201 before the Baglers surrendered. In the 13th century, King Haakon Haakonson set up a castle in T�nsberg, T�nsberg Fortress. The town was destroyed by fire in 1536, but T�nsberg remained one of the most important
