The Wars Of Apostasy, named simply The Rebellion by the heretics, 29,134 AD, lasted for 324 years. It's started when the phylarch of the fourth legion, Agamemnon Davarias, was exposed to and corrupted by the fickle influence of The Pantheon in Loki's Heresy. The following article details The War in as complete a fashion as possible.
The Arch-heretic began his secession began succinctly, with small whispers into the ears of his brother Phylarchs. Eventually, once he had secured the loyalty of Eros, Kakohl, Forrel and Orion, he took the planet Kaihnne, and his warpath began.