Dominion

The Dominion was a major interstellar state in the Gamma Quadrant. Technologically advanced and millennia old, the Dominion was founded under the absolute rule of a group of Changelings known as the Founders, whose will was carried out by the Vorta and the Jem'Hadar. The Dominion was dedicated to imposing the Founders' vision of "order" upon the universe, i.e. bringing all other civilizations under its control. Source: Memory Alpha