The Galactic Commonwealth
The Galactic Commonwealth is a faction which arose from the earlier Terran Rebellion/Terran Resistance Forces which were formed in the 2370s. The faction mainly comprised of Terrans and the species they had previously conquered, now having to rise up against the KCA who had overthrown them in turn. They are the second-largest faction in the Mirror Universe, having formed alliances and reclaimed a lot of space that was previously owned by the Terran Empire.
While initially they used the same brutal approach as the other factions, their ideals began to turn to diplomacy and peace in 2378, influenced by the Prime Universe’s UFP and previous attempted reform in the Terran Empire. One of their most notable victories was managing to encompass more than two-dozen planets in a twenty light-year span from Sol. Slavery has been outlawed, all species are equals, and the focus is on peace and forming alliances. The Galactic Commonwealth are the ones who have called for the peace summit on Starbase 777, hoping that they can share their ideals and convince the other factions to lay down their arms and set a new precedent for the Mirror Universe.
The Galactic Commonwealth comprises a number of species. This includes Terrans, Bajorans, Vulcans, Tellarites, Andorians, and others who may have been - or had family who were - part of the Terran Resistance or former slaves of the Klingon-Cardassian Alliance. They may be newer members who have turned away from the Terran Empire’s ideals. Klingons, Cardassians, and Bajorans may have joined their ranks after turning away from the KCA. Romulans can also notably be found within their ranks, having formed an alliance with them early in the Commonwealth’s establishment.
Starbase 777 is the seat of the Peace Summit - a station that represents change, having swapped hands from the Terran Empire to the KCA to the Commonwealth over the years. Any Galactic Commonwealth officer who is attending will be a crewmember from this station.