The War of the Jewels

In 'The War of the Jewels' Christopher Tolkien takes up his account of the later history of 'The Silmarillion' from the point where it was left in 'Morgoth's Ring'. The story now returns to Middle-earth, and the ruinous conflict of the High Elves and the Men who were their allies with the power of the Dark Lord. With the publication of this book all J. R. R. Tolkien's later narrative writing concerned with the last centuries of the First Age, the long history of 'The Silmarillion', from it's beginning in 'The Book of Lost Tales', is completed; and the enigmatic state of the work at his death can be understood.
The book contains the full text of the Grey Annals, the primary record of the War of the Jewels, and a major story of Middle-earth now published for the first time: the tale of the disaster that overtook the forest people of Brethil when Hurin the Steadfast came among them after his release from long years of captivity in Angband, the fortress of Morgoth.
"One marvels anew at the depth, breadth, and persistence of J. R. R Tolkien's labour. No one sympathetic to his aims, the invention of a secondary universe, will want to miss this chance to be present at the creation."
'Publishers Weekly'