Kabal of the Talon Cyriix
The Archon of the Kabal of the Talon Cyriix, Ysclyth, was tired of the tyrannical dictator of Commorragh, Asdrubael Vect. He managed to summon an army of daemons and attacked with his kabal and daemon-allies. However, Vect had already prepared for such a situation, sealing the attacking Archon's forces in their home district, at which point their daemonic allies turned on them.
Now the district of Talon Cyriix is silent and deserted, with only skulking wretches and slaves lurking in its catacombs and courtyards. After many millennia of pure-blooded lineage the whole family had been wiped from existence, all because of the hubris of one of its descendants.