House War

The House War of 31 IY was a short and bloody triggered by the first death of the Emperor. Seven Noble Houses attempted to destroy the Emperor's cloning facility on Mercury and initially three Houses stood against them.

Once it became clear the initial attack failed The Shepherds, who had remained neutral, joined the loyalists.

After several months of devastating fighting the traitors were betrayed by The Veil, which let them survive the purge at the end of the war.

Loyalist Houses

 * The Black Saints
 * The Legion
 * The Order
 * The Shepherds (joined in the war late)

Traitor Houses

 * The Battalion
 * The Ebon Wings
 * The Illustrious
 * The Sanguine
 * The Shroud
 * The Union
 * The Veil (joined the Emperor at the end of the war)