Snorri Sturluson,
Heimskringla — King Olaf Trygvason's Saga…
“ Olaf Trygvason Elected King. Olaf Trvgvason was chosen at Throndhjem by the General Thing to be the king over the whole country, as Harald Harfager had been. The whole public and the people throughout all the land would listen to nothing else than that Olaf Trygvason should be king. Then Olaf went round the whole country, and brought it under his rule, and all the people of Norway gave in their submission; and also the chiefs in the Uplands and in Viken, who before had held their lands as fiefs from the Danish king, now became King Olaf's men, and held their hands from him. ”
