Complex sentence: Herman Didrich Janson was also the owner of Stiftsgården from 1805, an estate which he sold in 1809 to his stepson, County Governor Edvard Hagerup.
Split into simpler sentences: Herman Didrich Janson var was also the owner of Stiftsgården from 1805. He sold the manor in 1809 to his stepson, County Governor Edvard Hagerup.