The Space Marine Legions of the 31st Millenium field a diverse and formidable range of genetically-enhanced warriors and advanced war machines, superior to any other military force in the galaxy. As an Age of Darkness falls across the stars and the fires of rebellion rage out of control, the armies that were used to forge the Imperium turn upon each other in an apocalyptic civil war – the Horus Heresy. Of the eighteen Space Marine Legions, only half remain loyal to their oaths. Heroes without equal, these Space Marines rally to defend the Emperor and all he has strived to build. In the turmoil of the Horus Heresy, the Loyalist armies stand firm against a tide of corruption and betrayal, waging bitter war against their former brothers – those that have forsworn their oaths and turned upon the Imperium. By the courage and might of these steadfast warriors will the fate of the Imperium, and that of humanity itself, be decided. This book is an essential guide for anyone who wants to command a Loyalist Legiones Astartes force in Warhammer: The Horus Heresy. It contains all of the rules you need to field every unit and formation available to Loyalist forces, from core units and weapons shared by every Space Marine Legion to specialist rules for each of the Loyalist Legions – including Rites of War, unique wargear, signature units, and their legendary Primarchs. Inside this 344-page hardback book, you'll find: – Rules and unit profiles covering every unit, weapon, and piece of wargear available to the Loyalist Legiones Astartes in Warhammer: The Horus Heresy – Legion-specific special rules, Warlord Traits, Reactions, Rites of War, wargear, unit profiles, and unique characters for each of the Loyalist Legions: the Dark Angels, White Scars, Space Wolves, Imperial Fists, Blood Angels, Iron Hands, Ultramarines, Salamanders, and Raven Guard – Profiles for each of the Loyalist Primarchs: Lion El’Johnson, Jaghatai Khan, Leman Russ, Rogal Dorn, Sanguinius, Ferrus Manus, Roboute Guilliman, Vulkan, and Corvus Corax – A visual showcase for each Loyalist Legion, containing heraldry markings, colour schemes for infantry and vehicles, and a small gallery of stunning miniatures photography In order to use the contents of this book, you will require a copy of the Warhammer: The Horus Heresy – Age of Darkness Rulebook.