With the publication of the final volume of the twelve-volume History of Middle-earth, Tolkien fans and scholars found themselves with a truly wonderful resource. Comprised of much of the unpublished writings and notes of J.R.R. Tolkien concerning his fictitious world of Middle-earth, the History is a multi-faceted work. It can be read simply as a complex mythology (if one merely skims over the scholarly notes), or it can be read as a light into one of the most mythical minds of the twentieth century. Either way, it is a wonderful resource.
But twelve volumes can be daunting to refer back to if the reader wants to look up a particular passage. Someone who has read the complete series would not have a problem knowing to go to volumes 2 and 3 (The Book of Lost Tales, Vol. 2, and The Lays of Beleriand, respectively) to read the major accounts of the tale of Beren and Tinuviel, but suppose the reader wanted to trace the full development of Earendil as a character. One option would be to lug out all twelve volumes and thumb through the indexes at the back of each volume. This, however, quickly becomes cumbersome because the reader has to jump back and forth between index and text, which limits the reader's ability to cross-reference between volumes.
HarperCollins, however, has had the brilliant idea of taking the indexes from all twelve volumes of the History and re-sorting the entries into one master index, published in a separate volume as The History of Middle-earth Index.
The Index contains every entry from the separate indexes of the History, as well as Christopher Tolkien's explanatory text that prefaces each separate index. However, instead of gathering all the references to a particular name under one heading, Tolkien has chosen to keep the entries separate. Thus, we have a separate heading for Beren's appearances in the first volume, followed by an entry for Beren's appearances in the second volume, etc. At first, I thought this would be a nuisance and make easy referencing more cumbersome, but after a little work with the Index, I discovered such a layout very helpful. To begin with, the reader can isolate easily all the references in one particular volume while still having easy access to the references in other volumes without having those other references get in the way and produce clutter. Furthermore, such a layout allows one to trace the development of a character through the Index. Earendil, for instance, we see was originally Earendel until volume ten (Morgoth's Ring) at which point he became Earendil. From this we can make inferences about the evolution of Tolkien's progress in the development of the languages of Middle-earth.
The Index is full of such unexpected moments of joy, moments where a Tolkien fan, merely by seeing index entries from different volumes listed sequentially can say, 'Ah! I never made that connection before!'
The Index is definitely a must-have resource for anyone interested in moving "further up and further in" (to borrow a phrase from another Inkling) to Tolkien's legendarium. At the moment, however, it is not available in a United States edition. This, however, should not be a concern, especially since the page references are consistent across all editions of the History except for the Del Rey mass-market paperbacks. I was able to check against the U.K. HarperCollins editions (softcover only), the U.S. Houghton Mifflin editions (both hard and softcover), and the Del Rey paperbacks. This limitation of the Index, however, would probably not be too much of a problem since (I assume) anyone who would be interested enough in Tolkien's legends to buy a book that is nothing but an index probably wouldn't have the Del Rey paperbacks as the sole copy. (Having said that, I discovered while conducting research for this review that I must have loaned my hardback of The Book of Lost Tales, Volume 1 out and never got it back, since all I now have is the Del Rey paperback. Sigh.)