The Broken Sword
Poul Anderson
 The book tells the story of Skafloc, elven-fosterling and originally son of Orm the Strong. The story begins with the marriage of Orm the Strong and Aelfrida of the English. Orm kills a witch's family on the land and later half-converts to a Christian, but quarrels with the local priest and sends him off the land. Meanwhile, an elf named Imric, with the help of the witch, seeks to capture the newly born son of Orm. In his place, Imric leaves a changeling called Valgard. The real son of Orm is taken away to elven lands and named Skafloc by the elves who raise him. As the story continues, both Skafloc and Valgard have significant roles in the war between the trolls and the elves.