The First Colonies were the first interstellar and intergalactic colonies established on various planets, moons, asteroids, and space stations in at least 12,000 solar systems by Star Elves and Asguardian Dwarfs between 351 years before Year 1, when Hyperdrive was first invented, and Year 1, when the Star Imperium was founded. The First Colonies were mainly in the galaxy And 10, the location of Alfheim and Asguardia, and the Andromeda Galaxy.

This was the time of first contact with races of Aliens, particularly Orks.

This was also a time of conflict with the Orks and with breakaway groups of Star Elves and Asguardian Dwarfs including the Dark Elves, the Sigmarites, and the Sul-Menites. The wars pitting these groups with members of the First Colonies who remained loyal to the authorities on Alfheim and Asguardia led to the creation of the Star Imperium.