Luna - First Pacification of Luna: To the task of conquering Luna, the Emperor set three of His newborn Space Marine Legions most suited to this purpose on what some Imperial chroniclers name as the first true battle of the Great Crusade. The combined force of the VII, XIII and XVI Legions (later named the Imperial Fists, Ultramarines and Luna Wolves) lifted from the surface of Terra in a scattering of rocket flame. The as-yet-unnamed XVI Legion had been chosen to serve as this Space Marine force's vanguard, and had brought its full strength to bear.Cutting power to their assault craft, the Astartes of the XVI Legion drifted silently towards Luna from Mankind's birthworld through the void like arrows fired into the night. As the smaller wave of assault craft belonging to the VII and XIII Legions approached the airless world, the Selenar defensive weapon systems embedded in Luna's surface lashed the oncoming Imperial force.The XVI Legion's assault craft, unlooked for and unseen, struck their targets like a dagger in the night. Within six solar hours of the first shot being fired, Luna had been pacified and brought into Imperial Compliance, the first off-world conquest of the Imperium of Man.Faced with annihilation, the surviving Selenar cultists bent the knee instead, their surrender communique transmitted to Terra calling for the Emperor to "call off his wolves." Broken and humbled, the enslaved gene-wrights of Luna would help forge the next generation of Space Marine who would carry out Mankind's conquest of the stars. As for the XVI Legion, they had earned their name -- the Luna Wolves.For a time in the Age of Strife when Terra was engulfed in war and blood, the Moon had become desolate and empty once again despite the small population of Selenar, but after the rise of the Emperor and its conquest by the Imperium, Luna knew a rebirth. Waxing and waning, the satellite came full circle as the Age of the Imperium brought it new life.Bisecting the grey stone sphere across its equator lay a man-made valley many kilometres wide. This was "the Circuit," an artificial canyon that laid open the rock and stone beneath the dusty lunar surface. All along the length of the chasm lay gateways into the Moon's interior, vast doors to the honeycomb of spaces carved by Mankind in the heart of Luna.The ancient, dead boulder of the Moon became the largest military complex ever built by humans. A vast orbital shipyard for the armada of the Imperium, thousands of starships from the smallest shuttle to the largest Battle Barge, were built and maintained there, and across the face of the Far Side there were complex stations for observation of the great void beyond.Port Luna was the cold, stone heart of humankind's great fleets. The satellite was as much a weapon as it was a safe harbour. Much of the metals mined from the Moon's heart and the rock from the Circuit's excavation had been employed by the Emperor's most-skilled engineers, fashioned into a synthetic ring that girdled the planetoid.The vast, grey hoop held batteries of Lance cannons and docking bays for more warships. Wherever the light from Luna fell, those who saw it could sleep soundly knowing the ceaseless guardian stood to their defence. And beyond it lay the sacred soil of Terra itself.During this period in the era of the Great Crusade, Luna was home to the Sisters of Silence, known also as the Silent Sisterhood. They were the militant arm of the Adeptus Astra Telepathica and were internally referred to as that organisation's Departmento Investigates.Their base of operations, the mighty brass fortress-monastery known as the Somnus Citadel, was located on Luna. Within the mighty fortress were multiple tertiary landing ports designed for shuttles deployed aboard the Black Ships, the dread starships that make up the fleet of the League of Blackships, which forms the recruiting division of the Adeptus Astra Telepathica.