Olaf, according to the Danish king Sweyn Estridson and Adam of Bremen, was a Swedish chieftain who conquered Denmark in the late 9th century or early 10th century and founded the House of Olaf. He had the sons Gyrd and Gnupa, who ruled together according to Swedish tradition. Gnupa had the son Sigtrygg Gnupasson who is mentioned on the two Sigtryg...