The Badab War was a bitter secessionist conflict fought largely between Space Marines, one of the rare occasions when the Emperor's Angels of Death turned their guns upon their own. It began when Lufgt Huron, master of the Astral Claws and overlord of the Badab Sector, refused to surrender the gene-seed tithes and taxes owed to the wider Imperium.
Styling himself the Tyrant of Badab, Huron drew several other Chapters to his cause and declared his region effectively independent. The Imperium answered by dispatching loyalist Chapters to bring the renegades to heel, and what might have been a swift policing action instead escalated into a grinding war that consumed more than a decade. Battle-brothers who had once fought side by side now met as deadly foes across contested worlds.
The fighting was fierce and morally fraught, for many of the secessionists were not corrupt but merely loyal to a charismatic leader who felt betrayed by an ungrateful Imperium. In the end the loyalists prevailed and Badab was brought back to heel, but Huron himself survived, terribly wounded, to be reborn as the infamous Chaos pirate lord Huron Blackheart. The war left lasting scars, with several Chapters censured, exiled, or sent on penitent crusades. For more, see the Badab War.