The Horus Heresy

The Horus Heresy is an ongoing series of science fantasy books written by various authors. The series takes place during the Horus Heresy, a fictional galaxy-spanning civil war occurring 10,000 years prior to the far future setting of Games Workshop's Warhammer 40,000 tabletop miniatures wargame. It is also a game system using the Wh40K ruleset.