If you are entranced by the Tolkien mythologies of The Hobbit and Lord of the Rings, you need to read this book. Many of the intriging but passing references made in the before mentioned tomes are illuminated in this book. It is a history, if only partial of the making and developement of Middle Earth. Many of the characters only mentioned in the more familiar books are 'fleshed' out here and take on a life of their own, as Tolkien is wont to do.