Wolvern

Wolvern was the Duke of Trondheim in the 12th century and the father of Princess Freydis. He had united the warring tribes, brought peace to the region and established trading with their neighbours. To strengthen the peace, he arranged a marriage between his daughter and King Gissar Polvaderson of Iceland. (PROSE: Dark Horizons)

Behind the scenes
The novel says that Freydis is the Duke's daughter in chapter one, but she is called the daughter of the king in chapters twelve and seventeen.