Originally published soon after the publication of The Silmarillion, this book is generally recognised as an excellent reference book on the subject. However, as it does not include information on post-Silmarillion material (e.g., Unfinished Tales and the The History of Middle-earth series), there are errors in certain places.
The book was first published as A Guide to Middle-earth in 1971, with paperback being released in 1973. In 1978, the title was emended to The Complete Guide to Middle-earth: from The Hobbit to The Silmarillion. A revised edition was published in 2001, as well as an illustrated edition in 2003, in time for the Lord of the Rings movie trilogy (ISBN 0-345-44976-2).