Terra
In the 41st millennium, Terra is the name for Earth, and it is the holiest place in the entire empire. After all, it is the homeworld of humanity and the seat of the Emperor. Pilgrims from all corners of the empire make their way to Terra. The entire planet is like a single temple: Every piece of ground, no matter how barren, is considered sacred.
Once, many different nations coexisted on Earth. However, in the 20th millennium, a time of great turmoil began, known as the “Age of Strife.” During this time, civilizations throughout the galaxy fell, including the original realm of the Eldar (the Space Elves were once the most powerful race in the galaxy).
At that time, humanity on Terra also faced the threat of self-destruction. However, the Emperor prevented this by calling for a great crusade towards the end of the 30th millennium.
With his thunder warriors, the Emperor first united Terra and then many other worlds inhabited by humans under his rule. Thus, the Imperium of Man was founded.