The Stellar Commonwealth was a multi-species republican government founded in 649 in response to the Lukasian Depredations and continued arcton raids. For sixty-five centuries, the Commonwealth represented the settled and explored galaxy, and constantly pushed to expand the frontier. However, political corruption and conspiracies brought it to the brink of collapse on several occasions. The final straws were the War of Secession and the following Psion Insurrection, which saw the culmination of Premier Stefan Farrol's plan to install himself as the sole leader of the galaxy.
The Commonwealth was succeeded by the Celestial Empire.