Armies of the Imperium

The Imperium is an authoritarian human empire of about a million worlds that has existed for over 10,000 years. Its culture is highly religious, with the Emperor of Humanity, an extremely powerful psyker who is worshipped as a god, as its main deity. Anyone who does not worship the Emperor properly is liable to be persecuted for heresy. The Emperor founded the Imperium and is still its nominal leader, but about two centuries after the founding of the Imperium, he was mortally wounded in battle and has been on life support in a state of unconsciousness ever since. Despite his condition, his mind still generates a psychic beacon that allows ships to navigate the Warp, making him the backbone of the Imperium's infrastructure. Although the Imperium has very advanced technology, it has long since ceased to practice science and its technologies have not improved in thousands of years. Imperial citizens are taught to obey authority without question, to worship the Emperor, to hate and fear aliens, and to take no interest in anything that does not concern their duties. Most Warhammer 40,000 novels have Imperium humans as the protagonists, with other races as antagonists or secondary characters.