An acclaimed bioarchaeologist, Catrine Jarman has used cutting-edge forensic techniques to spark her investigation into the history of the Vikings who came to rest in British soil. By examining teeth that are now over one thousand years old, she can determine childhood diet—and thereby where a person was likely born. With radiocarbon dating, she can ascertain a death-date down to the range of a few years. And her research offers enlightening new visions of the roles of women and children in Viking culture.

Three years ago, a Carnelian bead came into her temporary possession. River Kings sees her trace the path of this ancient piece of jewelry back to eighth-century Baghdad and India, discovering along the way that the Vikings’ route was far more varied than we might think—that with them came people from the Middle East, not just Scandinavia, and that the reason for this unexpected integration between the Eastern and Western worlds may well have been a slave trade running through the Silk Road, all the way to Britain.

Told as a riveting history of the Vikings and the methods we use to understand them, this is a major reassessment of the fierce, often-mythologized voyagers of the North—and of the global medieval world as we know it.