The idea is that the Master Of Orion 2 Races were around before the Council took power and found the Citadel. The Ssaros hated the Bulrathi, as the two were both trying to be the military race for the (MoO II) Council, to defend against the Antarans. Ssaros used Ultra-elite, heavily armed and armored Marines, with smaller fleets of better built ships (Ssaros had a rep as the best warriors, referring to a battle, with about 10 or so enemy Battleships with destroyer and cruiser support were smashed by 4 Ssaros ships, based off an actual battle I had against Humanity). Bulrathi used bigger amounts of less trained, heavily weaponised ships, and for Marines, wave attacks with high power shotguns and machine guns (their Homeworld was at about 3.1Gs, relative to ours, so they have massively powerful firearms to counteract their gravity) backed up by massive tanks. However, the Bulrathi were united behind Terios, and (At the Time) the Ssaros had an Emperor Ssarezaar. The two came to blows, the Ssaros relegated back to a Feudal Empire (Every planet has a representative in the Council of Karigdar, Ssaros Homeworld), and Ssarezaar became a warrior. After a bloody conflict, the Antarans arrived en masse. (IE a fleet bigger than the Migrant Fleet) Since the Ssaros' fleets were roughtly one-to-one in power, and the Antarans deploying planet-crackers, the Ssaros fled, at about 54 Million (Three planetoid bases, each at 18 million. Ssaros had small population numbers) That was 150 years after the first Bulrathi-Ssaros War. After 1000 years fleeing them, a sudden change in decision made the Ssaros fight them Head ON! After their victory, they returned via the now named Karigdar-6 Relay. After another bloody war, they reclaimed three planets: Karigdar (Homeworld) Woo, and Jiak'Vos. They returned to a drastically changed galaxy, with the Council (Turians, Asari, Salarians) in power. not too long after, the IA was formed, etc cut to now. Any more detailed questions? also sorry for the info-dump
Dsarker: "Very well, sir. I shall read this. Excuse me." He leaves to his room