The Horus Heresy is a 65-book series with 63 released primary works first released in 9 with contributions by Graham McNeill, Dan Abnett, Ben Counter, James Swallow, Mitchel Scanlon, Mike Lee, Aaron Dembski-Bowden, Gav Thorpe, Nick Kyme, Chris Wraight, David Annandale, John French, Guy Haley, Anthony Reynolds, John French, Rob Sanders, Rob Sanders, Michael F. Haspil, Gary Kloster, Nicholas Wolf, Noah Van Nguyen, and Chris Forrester.