In this three-part drama-documentary series, Dan Snow explores the political intrigues and family betrayals between Vikings, Anglo-Saxons and Normans that led to war, and the Battle of Hastings. King Harold of England has to take on two invasion forces. First, his brother Tostig attacks the south coast. He is repelled, but there is more to come. Later in the year, a vast Viking invasion force led by King Harald Hardrada of Norway lands in the north of England. Harold rushes to Stamford Bridge to fight for his kingdom and for his life. Meanwhile, Duke William of Normandy is ready to invade, but storms keep his invasion fleet trapped in port.