Resembling a vast mountain range cast adrift in the void of space, the Basilica Mortis has been the ancestral home of the Mortifactors for nearly ten thousand years, since the Chapter's founder, Sasebo Tezuka, had been led to the planet Posul by the Emperor's Tarot. Since that time, the chapter has trained members of their warrior order within the walls of their orbiting fortress monastery. At full occupation, the monastery is home to the thousand battle-brothers of the Chapter and their officers, with a supporting staff of servitors, scribes, technomats and functionaries that number seven and a half thousand souls.
Inside the structure, the gently arched walls are smooth and sparsely ornamented save for skulls. Every portal and chamber a visitor passes through bears more skulls, none carved or fashioned by human hand. All are real, bleached and dusty with age. In addition, tiny niches built into the corridors hold stasis-sealed vessels containing some of the Chapter's holy relics. The halls of the Mortifactors are gloomy and silent as a tomb.
The Gallery of Bone is the main audience chamber of the Chapter Master of the Mortifactors. It is aptly named; a carved cloister of bone surrounding a stone flagged floor paved with hundreds of tombstones. Niches set within the columns of the cloister contain skeletal warriors clutching swords and the entire domed ceiling is formed from interlocked skulls, their eyeless sockets glaring down at those who stand within their domain. Mortuary statues of angels flank a vast throne composed of the bones of long-dead Space Marines. Everywhere one looks, death is venerated and exalted above all things.
- 1: Warriors of Ultramar (Novel) - The Ultramarines Omnibus, Chapter One
- 2: Storm of Damocles (Novel), Chapter One
- 3: Codex: Tyranids (5th Edition), pg. 28