Adeptus Astartes

Lore & Background

The Horus Heresy is a dark, far-future military space opera concerning a galactic civil war within the nascent Imperium of Man. It is caused by a Chaos plot to foil the Imperium's leader and founder, the mysterious Emperor of Mankind, by fomenting rebellion and internecine warfare. The story focuses on the Emperor's 20 genetically engineered sons, the Primarchs (though two were lost or expunged from records), and the legions of genetically enhanced superhuman soldiers that they lead, the Legiones Astartes, which find themselves divided into loyalist and traitor factions as they struggle for victory. The conflict is depicted as having lasted for approximately seven years, from the Istvaan III Atrocity to the Siege of Terra.

Reader's Guide

The Legiones Astartes are genetically enhanced superhuman soldiers led by the Primarchs, the Emperor's 18 genetically engineered sons. During the Great Crusade, they are at the forefront of expeditions, fielding huge fleets and vast armies. The Space Marines number in the millions. The Horus Heresy series consists of full-length novels and novel-length compilations of novellas or short stories, written by a number of authors. The first three novels form an opening book trilogy that presents some of the background and causes of the Heresy and describes the start of the conflict, focusing on Warmaster Horus, the principal antagonist.

Did You Know?

• The Horus Heresy series consists of more than 65 published volumes; as of 2024, the total number of novels, novellas, and anthologies exceeds 65, and the exact count is not a fixed canonical figure.
• The Horus Heresy tabletop wargame was launched by Forge World in 2012 and relaunched as Warhammer: The Horus Heresy in 2022.

Origins and Narrative Scope

The Horus Heresy is a series of science fantasy novels set in the fictional Warhammer 40,000 setting of tabletop miniatures wargame company Games Workshop. The series takes place during the Horus Heresy, a fictional galaxy-spanning civil war occurring in the 31st millennium, 10,000 years before the main setting of Warhammer 40,000. The war is described as a major contributing factor to the game's dystopian environment. The shared universe was originally created in 1987 by Games Workshop. The series includes new characters as well as establishing the background of previously established Warhammer 40,000 characters who play an important role in the post-Heresy fictional universe.

Publication History and Evolution

The books are published in several media by the Black Library, a Games Workshop division, with the first title released in April 2006. The series consists of 65 published volumes; the concluding story, The End and the Death, was released in three volumes, with the concluding volume of the series, The End and the Death: Volume III, being released in January 2024. The series has developed into a distinct and successful product line for the Black Library; titles have often appeared in bestseller lists, and overall the work has received critical approval despite reservations. A sequel series, The Scouring, began publication in December 2025.

Adaptation into Tabletop Gaming

The popularity of the novel series contributed to the development of The Horus Heresy as a tabletop wargame spin-off of the Warhammer 40,000 miniature wargame, launched by Games Workshop's subsidiary Forge World in 2012. Initially it was a specialist game supported through a series of campaign and army books detailing the events of the conflict, alongside a dedicated range of resin miniatures. The game later evolved into a standalone system with its own ruleset and product line, and was relaunched as Warhammer: The Horus Heresy in 2022. Furthermore, publisher Cubicle 7 announced The Horus Heresy Tabletop role-playing game to be released in 2026.

Multimedia Production and Contributors

Contributors of the series include artists, audiobook narrators, and compilation or abridgement editors.