At the heart of the Imperium is Holy Terra, the crucible of the human
race and capital of the greatest human empire ever to hold sway over
the galaxy. Here the Priesthood of Earth—the Adeptus Terra—rules,
the highest-ranked lords passing proclamations that touch the lives of
untold billions every day, albeit indirectly. Endless divisions of the
Adeptus Terra are represented on Terra, as are numerous other bodies,
such as the Adeptus Ministorum.
Aside from the billions of scribes and administrators that make up the multitudes of Terra, this mightiest of Hive Worlds swarms with pilgrims of every stripe. Some are hyper-wealthy nobles, come to honour the birthplace of Humanity and to breathe its sanctified air. Most are desperate penitents, come to Terra with no greater intent than to voice their adoration of the Emperor with their dying breath. Many are the descendants of the faithful who set out upon their pilgrimage many generations before, not caring how arduous the journey truly was. Having perished along the way, these pilgrims passed their holy quest on to their heirs, who grew up knowing nothing more than the trail upon which thousands more fall each day.
Other wondrous places are to be found within the Sol system, bathed in the same light that incubated Humanity at the earliest stages of its pre-history. The red planet, Mars, is the greatest of forge worlds and the heart of the Cult Mechanicus. Terra’s moon, Luna, is host to the mightiest of defences, in the face of which no foe can hope to assault Earth. Jupiter is host to the Jovian Shipyards, where some of the most gloriously feted warships in the Imperium’s service are wrought. Saturn houses countless dark secrets, held secure by the most determined of the agents of The Inquisition. Saturn’s moon, Titan, is the secret home of the Grey Knights Chapter, the elite Daemon-hunting Space Marines of the Ordo Malleus, and their impregnable fortress-monastery.