The Imperium of Man is a fictional empire in the Warhammer 40,000 universe, a dystopian science fiction setting. It represents a vast, authoritarian regime that spans the galaxy, uniting humanity under a single rule. The Imperium is characterized by its rigid hierarchy, religious devotion to the God-Emperor, and a constant struggle against various alien species and heretical factions. The Imperium is known for its massive military forces, including the Adeptus Astartes (Space Marines) and the Imperial Guard. It relies heavily on ancient technology and is marked by a culture of superstition and fear. The Imperium's primary goal is to protect humanity and maintain order in a chaotic universe.