In this episode, the Vikings get a visit from our most interesting character so far. Ansgar is the fascinating first Christian missionary to Sweden, who tirelessly tries to spread his religion throughout Sweden, in the town of Birka. We meet many other interesting characters, including the Viking "Kings" Björn and Anund, Father Witmar, Gautbert, King Louis the Pious and a host of supporting characters in this exciting story of exploration, violence and religion. We also look in detail at Birka itself to see what life was like in Viking towns.