Ceres

Ceres is the smallest of the dwarf planets and is also the most important world in the Asteroid belt. First colonized in 2042, it quickly became a major refinery for minerals mined both on its own surface and the other asteroid colonies. Sapient2 mining colonies were discovered on its surface. Today, Ceres has been terraformed and houses 250 million humans and is the capital of the Neo-Delian League. The entire asteroid belt is home to a total of 723 million humans.