Niels Toreson BERGE

I have traced one of my lines back to Vestre Slidre, Oppland, Norway. The wife of Niels Toreson BERGE, Kari Knudsdatter BERGE, I have been able to trace back, but am unable to trace Niels Toreson BERGE back at all. Any help would be apprecieated. The only reference is that he was born probably sometime before 1790 and was married to Karie Knudsdatter BERGE on 22 Oct 1808 in Nord Aurdal, Oppland, Norway.