Almost everybody has heard of the Vikings, and what they have heard is usually bad: raids of plunder and pillage, murder and slavery, longships disgorging bands of barbarian marauders to chase the English and frighten the clergy—images that are resolutely violent, maritime, and male. There is some truth in this, to be sure, but the Scandinavian peoples who expanded so dramatically into the northern world from about 750 to 1050 A.D. were also traders, settlers, artists, and poets, possessed of a sophisticated and subtle culture with a gender spectrum as broad as our own.

In the course of more than 30 years spent researching the Vikings, what I still find most exciting, and surprising, is their own sense of who they were, of what it meant to be human. The Viking soul was a complex and many-layered place, populated with a bewildering variety of beings described in Old Norse poetry and in medieval Icelandic sagas.