Olaf Tryggvason (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. He is numbered as Olaf I.

Olaf was important