We think of Norse mythology as ancient and anonymous. But in fact, most of the stories we know about Odin, Thor, Loki, and the other gods of Scandinavia were written by the 13th-century Icelandic chieftain Snorri Sturluson.
Notice I said “written” and not “written down.” Snorri was a greedy and unscrupulous lawyer, a power-monger whose ambition led to the end of Iceland’s independence and to its becoming a colony of Norway.
But Snorri was also a masterful poet and storyteller who used his creative gifts to charm his way to power. Studying Snorri’s life to write my book Song of the Vikings: Snorri and the Making of Norse Myths, I learned how he came to write his Edda, a book that’s been called “the deep and ancient wellspring of Western culture,” and his Heimskringla, a history of Norway from its founding in the far past by Odin the Wizard-King.
These two books are our main, and sometimes our only, source for much of what we think of as Norse mythology—and it’s clear, to me at least, that Snorri simply made a lot of it up.