Though the Heresy was ignited by the product of a conspiracy by the forces of Chaos, there were precipitating factors that helped push many of the Legio Astartes towards rebellion. 5.6 The Muster on Ullanor and Lorgar's coup (013.M31).5.3 The Battle of Trisolian and the Wolf Cull (012.M31).5.2 The Dissolution of Imperium Secundus (011.M31).4.22 Nocturne and the Journey of Vulkan (~010.M31).

4.19 The Formation of Imperium Secundus (009-011.M31).

4.17 The Breaking of Anvillus (009.M31).

4.12 Capture of the Perfect Fortress (008.M31).

4.10 Shadow Crusade and Crusade of Iron (007-009.M31).

4.8 Furious Abyss and Battle of Calth (007.M31).

4.7 First Siege of Hydra Cordatus (~007.M31).

4.6 Battle of the Alaxxes Nebula (007.M31).

Massive, Traitors banished to the Eye of Terror Massive, Emperor forced to ascend to the Golden Throne Master of the Astronomican Cohran Hursula Master of the Administratum Simion Pentasian

The Emperor confronts Horus aboard the Vengeful SpiritĮmperor interred to the Golden Throne

Horus heresy