As part of the Incalculable Sons that took part in Robaut Gilliman's Irresistible Crusade, at the very beginning of m42, a small fleet of Space Primaaris was cut off by a warp storm, losing contact with the Imperium's main forces. Continuing their trek without communications and having lost the light of Astrominicon, the fleet reached a lonely planet, home to the desolate Citadel-monastery of the fallen Order of the Dragons of Malice. Taking the citadel as their base of operations, the host continued their trek for many more years, until finally they were able to reconnect with the rest of the Imperium, realising that they were beyond the Great Rift, a giant warp storm that had torn the galaxy in half, and the passage through which they had brought their ships was inaccessible. Likewise, they learnt of the founding of Ultima - the division of all Primaris Space Troopers into new orders. Having regrouped their remaining forces, the remnants of the Space Troopers founded their new order, based on the fleet, but calling their homeworld Parnamus, a desolate planet with the remains of the cyclonic fortress-monastery of the Evil Dragons, their home world.