|None, formerly Valnum
During the Great Crusade, House Cratax resisted the Imperium's efforts to assimilate their Knight World, Valnum, and executed its emissaries. This led sixty warriors of the Thousand Sons, under Captain Ohrmuzd, to bring Valnum into Compliance. Due to their psychic abilities, though, the Thousand Sons were able to resist the House's attacks and this allowed them to destroy all of Cratax's Knights. Only three Thousand Sons had died by the end of the battle and Valnum was later renamed 72-9 by the Imperium.