In 1066, the rivalry between two brothers brought England to its knees. When Duke William of Normandy landed at Pevensey on September 28, 1066, no one was there to resist him. King Harold Godwineson was in the north, fighting his brother Tostig and Harald Hardrada at Stamford Bridge. How could this have happened? Why would Tostig turn traitor to wreak revenge on his brother?

Harold and Tostig were not always enemies; it took a massive Northumbrian uprising to tear them apart, making one an exile and the other his sworn enemy. After Edward the Confessor died and Harold took the crown, Tostig was intent on reclaiming his earldom. But he was on his own; his brother was not sympathetic. In fact, Harold allied with Tostig's enemies. What else could he do?