The Worm Ouroboros

The Worm Ouroboros is a heroic high fantasy novel by Eric Rücker Eddison, first published in 1922. The book describes the protracted war between the domineering King Gorice of Witchland and the Lords of Demonland in an imaginary world that appears mainly medieval and partly reminiscent of Norse sagas.
This is the book that shaped the landscape of contemporary science fiction. J. R. R. Tolkien acclaimed its author as "the greatest and most convincing writer of 'invented worlds' that I have read." Written in the best traditions of Homeric epics, Norse sagas, and Arthurian myths, it recounts compelling tales of warriors and witches.
The Worm Ourorobos is second only to the Lord of the Rings in the pantheon of 20th century English fantasy. You have never read anything like this before!