|Colour Scheme||House Info||Symbol|
|Knight World:||Damaetus III/II|
Hailing from Felweather Keep on the Knight World of Damaetus III/II, House Vyronii is one of the most ancient Knight Houses of Segmentum Obscurus. Settling their world during the Dark Age of Technology, over the course the Age of Strife the Knights of Damaetus III/II stood resolute against countless xenos invasions, most notably against the Mitu. Eventually the Dark Angels arrived, having vanquished the Mitu. Grateful, they joined the Imperium and the Great Crusade.
Fighting with distinction and bravery during the Great Crusade, the House under Grand Master Jahk refused to become vassals to any specific Forge World, even when they pledged to upgrade their impoverished world. Eventually, however, Jahk realized the survival of his House depended on greater patronage, and swore service to the Forge World of Cyclothrathe. However, with the Horus Heresy secretly underway, Cyclothrathe (having sided with the Traitors against the Emperor), attempted a surprise attack on Felweather Keep under the guise of a bonding ceremony. Only through the efforts of Jahk's son, Gios, did the house survive the betrayal. Jahk was killed during the battle, however, and it fell to Gios to lead the House during the Horus Heresy on the side of the Imperium. Their most notable action was taking part in the Battle of the Coronid Deeps.