Spotlight : Commonwealth
The Commonwealth is the next largest solar state controlled space next the Alliance of Worlds and has butted heads with nearly every colonial state and solar empire in the sphere. Though Aristocratic, it is a democratic society. Thought each colony world elects its own governor, the other colonial worlds have only marginal influence on those elections due to the votes counting as half if they haven't originated from that world.
When in a state of war, the Commonwealth can bring the might of its extremely diverse population and equipment to the fight.