The Imperium of Man is an interstellar empire that controls a large portion of the Milky Way Galaxy. It has existed for over ten thousand years, and has withstood countless threats from both aliens and Chaos. The capital of the Imperium is Holy Terra, the birthplace of mankind. It is covered in massive cities, and the Imperial Palace covers most of the Himalayas.
The Imperium is ruled by the Emperor, its founder and figurehead. However, he is currently in a state of living death, and so the actual governance is done by the High Lords of Terra. The only leaders more powerful than the High Lords are the Primarchs, the Emperor's sons, who had been missing for most of the Imperium's existence but have started reappearing.
Being a massive sprawling empire, an enormous and inefficient bureaucracy oversees all aspects of life for the average citizen. Conflict between organizations is not uncommon, nor is it uncommon for disaster to come from logistical errors, overzealous administrators, or simple incompetence. Still, for most of humanity, life in the Imperium is better than being enslaved or killed by various Xenos races or the forces of Chaos.
- Space Marines - superhuman armies that served under the Primarchs
- Imperial Guard - standard human armies that form the majority of military forces
- Imperial Knights - nobles who fight in battle walkers
- Adeptus Custodes - the bodyguards of the Emperor
- Sisters of Battle - the military arm of the Ecclesiarchy
- Sisters of Silence - a Great Crusade-era military branch that specialized in fighting psykers