Damnos

Damnos, lying in Ultima Segmentum, was first populated during the Great Crusade. The planet had always been a Mining World, but for even longer now, it has been classified a Tomb World. The Necron presence was first discovered in the north, whilst Mandos Prime's geothermic fusion stations were under repair following severe seismic activity. The Tech Priests rapidly claimed there right to the artifacts and extradited several specimens to the nearby Forge World, Goethe Majoris, for closer study. Soon after, under waves of atmospheric interference that clouded the entire northern hemisphere, the Necrons emerged. The planet went on alert, but the threat was incomprehensible, no warning had been received from the fallen hives, and any recon units deployed never returned. As more Hives toppled, word of the assaulted finally got through to the planetary Governor, whom deployed every regiment under his command. Within six months almost all of Damnos' vast manufactorum cities were in ruins, and the planetary capital of Kellenport under siege.

The Ultramarines arrive
The cruiser "Valin's Revenge" with the Ultramarines second company arrived just as the final assault on Kellenport begun. Captain Sicarius ordered the cruiser into orbit above Kellenport to begin ground assault. The second company launched in three groups of drop pods. The first with Captain Sicarius himself, struck the Necrons in the very heart, scouring the machine-warriors from the capitals outer walls. The second under Chief Libarian Tigurius, hit home amidst the gauss siege cannon and Pylons whose fire rained down where the defenders of the capital still held out. The third wave, consisting entirely of unmanned Deathwind Drop pods, slammed into the broken rubble outside the besieged capitolis admistratum, fireing waves of missiles into the Necron ranks. The first strike force advanced against a Necron command nod. Their target was an Necron Lord commanding the assault. Captain Sicarius assaulted his position with his most experienced battle brothers and the Dreadnought Agrippan. Sicarius got badly wounded in the assault and for a moment it looked like the Necrons would score the victory, but the Dreadnouhgt Agrippan attacked the Necron lord and with a single mighty blow he destroyed the Necron lord. With their commander destroyed the Necrons reverted to secondary protocols and and begun to retreat. Captain Sicarius was taken to the cruisers medical bay and Tigurius took command over the remaining Ultramarines. Later Tigurius and Agrippan were forced to acknowledge that Damnos was lost. They begun evacuating as many of the planets inhabitants as possible. When the new Necron assault begun most of the planets inhabitants were evacuated, and only the Ultramarines and the Kellenports Guardsmen were still on the ground. The Ultramarines defended the city valiantly, slowly falling back to the spaceport. As the last Tunderhawk gunships landed to evacuate the survivors, only forty Space Marines and twenty guardsmen were still alive. In the final moments of the battle Agrippan fell, being pinned between a dozen streams of gauss cannon fire. As the Thunderhawks sped Tigurius and the last of the defenders to the safety of "Valin's Revenge", Agrippans reactor went critical- the resulting explosion oblivirated the capital and every Necron within it. Later Damnos was bombarded by the Imperial Navy destroying the planet and ending the Necron threat on Damnos.