The book is named after Lorath Nahr, the Horadrim who appeared in Diablo 3 during the Fall of Westmarch quest in Reaper of Souls and is also one of the dialogue narrators.
Book of Lorath Contents
Make your stand against the darkness with this comprehensive, stunningly illustrated artifact handed down by the Horadric Order, your key to the lore of Blizzard Entertainment’s Diablo® franchise
Amid the restless evil of Sanctuary, only the Horadrim—an ancient order of heroes and scholars—wield the knowledge needed to light the way for humanity. In the Book of Lorath, join Lorath Nahr, one of the last of the dwindling Horadrim, on a journey through Sanctuary’s most powerful relics and the stories behind them. It is Lorath’s hope that this volume will preserve his knowledge for all time . . . and pass it down to those who will inherit the fight against the Prime Evils.
Direct from the Diablo® development team and award-winning author Matthew J. Kirby, this immersive, must-have compendium with all-new illustrations showcases the artifacts that have often been—and might yet be—the key to tipping the fate of the world.
Hopefully, this is some indication of a Diablo 4 release window, it would seem fitting to appear around five to six months prior to release which is what's happened before with previous books.
Perhaps the content of this book is more suited to being available around the actual release date.
The Diablo: Book of Lorath will release on 18 April 18, 2023.
The Book of Lorath is listed on Amazon priced $29.95