received limited market town rights in 1715, and merged with Strømsø to gain status as a single city on 19 June 1811.

Its geographical location made the city favorable for seafaring, shipbuilding, log driving, timber trade. During the 19th century, paper and pulp industries were developed. Large parts of the city were ruined in the great fire of 12-13 July 1866, which led to the reconstruction of the city centre, including