This somewhat bulky book is comprised of the first four volumes of- "The Histories of Middle Earth" (twelve in total). Due to its size and rather overwhelming content it is only really suitable for the more devoted Tolkien reader. It is best read after reading "The Silmirillion" as the stories are all mainly based around the events therein. It takes a lot of time and effort to get involved in, with the earlier chapters being somewhat dry and uneventful, but after four-to-five days of solid reading it is thoroughly enjoyable. Since it is the product of four volumes I will review each of the volumes in turn.
Volume 1: The book of lost tales, part I
This first volume covers the first half of the Book of Lost Tales, introducing the mariner Eriol (of the race of men) who discovers the Lonely Isle (Tol Erresea) of the Elves and there is told the tales of their ancient history. It begins with the theory of creation, supposedly through the mantra of angelic beings (later called the valar) and continues through to the destruction of the bliss of Aman by Melkor (later called Morgorth), one of the valar, corrupted by greed and selfish desire. It tells also of the Noldor's (high-elves) revolt against the valar and their departure from Aman.
Volume 2: The book of lost tales, part II
This volume of the Book of Lost Tales narrates the fundamental tales of the Quenta Silmarillion. It includes the basic stories of Beren and Luthien, of Turin, and of the fall of Gondolin. It tells of the events and deeds of the banished Noldor and the decay and mortification of the world at the hands of Morgorth and his foul creatures. The volume concludes with the final battle between Morgoth and the Valar. It includes vast amounts of information on Elvish languages (mainly Quenya and Sindarin), which is sure to please scholars of his articulately constructed languages.
Volume 3: The lays of Beleriand
This volume comprises of some of the tales from the Quenta Silmirillion in poetic form; written by the elves of Beleriand before the battle between Morgorth and the Valar. The two most fully developed are the Lay of Lethian (the story of Beren and Luthien) and The tale of Turin Turambar. There is also a extensive evaluation of the Lay of Lethian, written by C.S. Lewis, which provides and in-depth look at some of the flaws and wonderful interpretations of the text.
Volume 4: The shaping of Middle Earth
It includes various prose fragments following the Lost Tales, which provide further insight into the "Sketch of the Mythology". It also includes The Annals of Valinor and of Beleriand which are a sort of parallel telling of the events. In their beginning they appear to be little more than a chronology, but they gather momentum as you continue, to reach a comprehensive narrative, which is indeed a real joy to read.
This is a wonderfully constructed book, and i recommend every avid Tolkien fan out there to read it, after all there is no better way to understand Tolkien's fantastic Middle Earth.