House Davion has ruled the Federated Suns since the nation's founding in 2317 by Lucien Davion, Prime Minister of New Avalon, who negotiated a mutual defense and assistance agreement with several nearby star systems. From their capital of New Avalon, the Anglo-French House Davion led the Federated Suns to become one of the largest and most militarily powerful states in the Inner Sphere. The Federated Sun traditionally sees itself as the champion of freedom, democracy, and human rights, especially compared to its authoritarian neighbors, although the reality is not so clear-cut. Additionally, the state's economic growth was uneven, with a small number of overdeveloped worlds making up for the larger number of underdeveloped ones. To counteract this deficiency and recover lostech, the pursuit of scientific knowledge was strongly encouraged by Davion leadership, and the New Avalon Institute of Science quickly became the premier research and development center of the 31st century.
For a brief period of time the Federated Suns joined with the Lyran Commonwealth to form the Federated Commonwealth, a massive super-state spanning the length of the Inner Sphere. There was internal resistance to this merger of the two realms, particularly in the Lyran half, which bore the brunt of the Clan offensive. In 3057 the Lyran worlds seceded from the alliance, splitting FedCom in two and creating the Chaos March. The split was made permanent after the FedCom Civil War.