The ultimate engines of war in the Imperium during the Horus Heresy are battle titans and knights, huge machines capable of levelling cities and obliterating entire armies. Sworn to the service of the hosts of the Great Crusade by binding oaths, the warriors who pilot these towering war engines follow their allies into the fires of the Horus Heresy.

This book is an essential guide for anyone who wants to command Titans and Knights in games of Warhammer: The Horus Heresy. It contains the rules you need to field the various deadly and esoteric machines and troops of the Questoris Familia and Legio Titanicus, whether they are loyal to the Emperor or the Warmaster. It includes Detachments, Wargear, and special rules which make these war machines a unique force on the tabletop.