Norderhov municipality was established on January 1, 1838 (see
formannskapsdistrikt). According to the 1835 census the municipality had a population of 7,234. On 22 April 1852 the city of
Hønefoss was separated from Norderhov to constitute a separate administrative unit. In 1857 the rural district
Ådal was separated from Norderhov, leaving Norderhov with a population of 6,846. In 1938 a part of Norderhov with 268 inhabitants was moved to Hønefoss, and on 1 January 1964 the rest was merged with Hønefoss, Ådal,
Tyristrand and
Hole to form the new municipality
Ringerike. Norderhov was by far the largest municipality prior to the merger, with a population of 15,143. ==Parish==