This story introduces Uhtred of Bebbanburg, a Saxon noble who is kidnapped by Danish Vikings as a young child and is assimilated into their culture, religion and language before a series of events lead him into the service of King Alfred of Wessex and his participation in multiple battles, including the notable Battle of Cynwit before the book's conclusion.

One day, Sven kidnaps Ragnar's daughter, Thyra, and removes part of her clothing in an effort to sexually assault her.

Afterwards, he takes part in a siege against Guthrum, and is among a group of hostages exchanged when the Danes and West Saxons make peace.

Staying with the Danes in the city over the winter, he again meets Ragnar, who saves him from death when Guthrum breaks the peace and murders the other Saxon hostages.

At the age of 20, during the 877 AD, he fights in the critical Battle of Cynwit, where he kills the renowned Danish leader Ubba in single combat.

Uhtred then rides to Exanceaster to find his wife and newborn son, instead of going immediately to personally inform Alfred of his victory as strongly advised by his wiser friend.

In July 2014, the BBC announced that production would begin in autumn 2014 on a television adaptation, to be titled The Last Kingdom.