The Phoenix Republic was a national state with its capitol world of Phoenix in the Phoenix Cluster, south of the Aquarius Cluster. The Republic was formed from the descendents of the Russio-Sino Alliance exodus vessel that left the dying Earth over 3000 cycles ago. Ultimately, the Republic would be reunited with the seperatistis from the Earth that eventually formed the Central Earth Government, and the two states would forge an alliance in the shadow of the UTN.

The Republic maintained a cool relationship with the Aquarian superpower, the UTN, cooling further with the Barrier 13 incident in 2601 A.D, when the Federation declared war on its long-term Ally, the CEG. Ultimately, the relationship between the two states would deterioate further until the UTN officially declared war on the Phoenix Republic in 3721 A.D after multiple terrorist attacks in UTN space. Over the next 500 cycles, the Republic would be dismantled and its space annexed by the Federation in one of the longest military campaigns in human history.