"Olaf Trygvasson (960s – 9 September 1000) was King of Norway from 995 to 1000. He was the son of Tryggvi Olafsson, king of Viken (Vingulmark, and Rånrike), and, according to later sagas, the great-grandson of Harald Fairhair, first King of Norway.
Olaf is seen as an important factor in the conversion of the Norse to the Roman Catholic religion. Many of these new converts were converted under threat of violence. He is said to have built the first Christian church in Norway, in 995, and to have founded the city of Trondheim in 997. A statue of Olaf Tryggvason is located in the city´s central plaza." - (en.wikipedia.org 31.01.2020)