The Alpha Centauri Concordium of Planets (or Centauri Concord) is a coalition of the colonized planets of the Alpha Centauri system -- with the exception of the planet Chiron. The first colony of the Concordium was the Manswell Expedition, which had colonized Alpha Centauri III after departing Earth in 2875 CE. When contact was reestablished, the colony retained its independence from Earth. As other planets in the system were colonized and declared their independence, the Manswell Expedition became the leaders of the emerging Concordium -- with Alpha Centauri III the capital planet and the city of New Samarkand becoming the capital city.
The Alpha Centauri Concordium is derived from Star Trek and expanded with information derived from Mass Effect.