Luna

Luna is the pale, cratered moon of Holy Terra, and the first world beyond the homeworld to fall under the Emperor's dominion. Its airless grey surface has been hollowed and domed into a warren of gene-laboratories, void-docks, and sealed hive-settlements, a place where humanity's oldest sciences were nurtured and, in time, mastered.

In the long night of the Age of Strife, Luna was ruled by the Selenar, gene-cults of extraordinary skill who reshaped human flesh to endure the void. When the Emperor turned His gaze skyward at the dawn of His conquest, He broke the Selenar's power, yet He also took their arts and their secrets into His service, and their knowledge is whispered to underpin the making of far greater warriors.

Throughout the Sol System, Luna serves as Terra's shield, its shipyards and gun-batteries forming the innermost ring of the throneworld's defences. Its vast void-docks have birthed warfleets since the earliest days of the Imperium, and the endless traffic of pilgrim-ships and warships between moon and homeworld never ceases. It was upon this moon that one of the Emperor's earliest Legions won its first great renown, earning by that campaign the name by which it would be feared across the stars, a bond that ties the history of the Adeptus Astartes to Luna's grey wastes.

Today the moon endures as it always has, its cloisters home to gene-wrights and its silent halls to sisterhoods sworn against the witch. These silent maidens, blank of soul and untouched by the warp, have kept their vigil upon Luna since the age of the Emperor's own conquests. Bound eternally to Terra by gravity and by fate, Luna shares whatever destiny awaits the world it circles. Should the Palace ever fall, the moon that guards it would not long outlive its master.