The War Wolf opens in January 1066 when Eorl Harold Godwinson of Wessex takes the crown from the dying king of England. He is not alone in his ambition, however. Across the sea, the duke of Normandy gathers an army.

An invasion follows, but it is not in the South of England where the conqueror sets foot, but in Northumbria. King Harald Haradrada of Norway lands the largest Viking army ever seen in Britain, and with his ally, Tostig Godwinson, the exiled brother of King Harold of England, steals the initiative by attacking York.

The young brothers, Eorl Edwin of Mercia and Eorl Morcar of Northumbria, see a chance to eclipse the mighty Godwins in battle by meeting the Vikings at Fulford Gate. Coenred, their captain of Huscarls, counsels otherwise. His warrior's wisdom tells him to bar the gates of York and man the walls with their Saxon army, but Edwin and Morcar cannot resist the lure of glory.

As the two great armies move onto the field at Fulford Gate, other characters pursue their dreams and desires, almost to spite the fate that is about to befall them. Mildryth looks for a protector in the face of the return of her husband's murderer, but her encounter with a noble heart inspires her to love again. Cruel is fate that inspires her to give her love to a foremost warrior, a man likely to stand before the spears of their enemies.

The fateful decision to fight sets in motion a series of events that will threaten the world of the Saxons, beginning with the Battle of Fulford Gate. Coenred must obey his lords, but his thoughts have already turned to the beautiful Mildryth; can he rise to be the best of warriors and survive an epic clash, sword to sword, with the War Wolf himself?