The Glitter Territories was formed by the Katoxyn and the Uathyn after first contact in 4029 CE. The Territories at first consisted of the entire star system but with the invention of their Warp Drive, they spread to their neighboring worlds and settled them, terraforming them to suit their needs.
The Glitter Territories is the loose translation of the actual name into the Xeno tongue, while a more accurate translation would be Lands of the Glitter, Glitter being their name for the Triangulum Galaxy.
What started out as just two species traveling and making treaties with each other soon turned into a vast galactic civilization, the center of government being a vast council with two members of each race holding an elected seat in the House. The Glitter Territories have a large interstellar navy on par with that of the Confederacy of Humanity.
With the vast differences in the species of the Territories, the government does not interfere too much in the affairs of planets but will if there is a risk of genocide or if anything threatens galactic stability.
In 10032 CE, the petition to join the Confederacy by the Glitter Territories finally passed, and the two powerful civilizations joined together, still carrying the Confederacy's name. Colonies sprang up in Triangulum and the Milky Way through many galaxy species interexchange programs.