And, here's another official info-dump incoming. Brace yourselves, and enjoy!
OTHER POWERS OF KNOWN SPACE
THE MERCANTILE REPUBLIC
Although the economic powerhouse that is the Republic of Sol is unrivalled, the Mercantile Republic could very well lay claim to being its nearest competitor. The broadily reptilian Iashec race emerged onto the galactic scene in 2001 CE, making first contact with the Barsa. They then proceeded to declare war on the Confederacy a mere three years later. The issue was never in doubt- the war was over inside of a year and the Iashec suitably humbled. Rather than spend the next centuries stewing in resentment over their defeat, they instead turned their attention to the serious and noble pursuit of making lots and lots of money, swiftly growing to become one of the major economic powers of known space. In the past two centuries, though, they have suffered two notable reversals of fortune- the first being the rise of the Republic of Sol. Still, the Iashec adapted- after all, Sol's lofty moral scruples kept it from trading in certain markets, ones that the Iashec had no compunctions whatsoever about- arms, narcotics, slaves. Then, along came the Ilwari. Initially they provided a much-needed trading partner and, after a little shift in the internal balance of power, a corporate power structure very similar to the Mercantile Republic's. Then, the Union formed and began to actively encroach on Iashec interests- competing with them in the galactic arms trade, and, even worse from the point of view of the Iashec, starting a dogged single-handed crusade against the slave trade. Lately, the situation has gone from bad to worse- with the Ilwari at the center of the Repatriation Treaty, said crusade is no longer single-handed. Overall, the Mercantile Republic has been feeling the squeeze, and the situation has left it increasingly angry and frustrated.
THE ENTAT STAR LEAGUE
For the past few centuries, the Entat have had very little impact on the wider galactic scene. Once, they were central to the galactic community, a solid pillar of the Trade Coalition that, up until the Hexamari Wars, served roughly the same purpose that the Consensus does now, in many ways. They created the first gravitic field drive, and from it the first sustained-field FTL system. Then, the Hexamari Wars happened. The Star League's domineering trade and economic policy, and it's willingness to aggressively protect and further its own interests was a trigger factor in the rise in Hexamari fundamentalism, and the Star League was the first power to fall victim to the now fanatical Theocracy's ruthless expansionism.
In the wake of the Hexamari wars, the Star League was much changed. While the Entat fought side by side with the other races to liberate conquered territories, they garnered much criticism when, once their old territory had all been reclaimed, they simply withdrew from the war, sitting back and leaving the rest the task of finishing the Holy Empire off. Ever since then, the Entat have been determinedly isolationist, and all that most races hear from within the Star League's space is stony silence- no-one knows what it's state is internally, or even how far Entat space now extends. For the time being, though, they seem perfectly content to keep themselves to themselves- there is some diplomatic contact periodically, but it always seems to happen on the Entat's terms.
THE HEXAMARI THEOCRACY
When they first joined the galactic community, the Hexamari didn't strike anyone as the sort of race that would go on to conquer a large portion of known space. Odd, rather too religious, and strangely obsessed with perfecting and enhancing their cybernetic technology, but not immediately threatening. Then the Entat happened. Religious fervor sprouted out of control into frothing, all-consuming fundamentalism, and, a mere 56 Earth years after first contact, a vast, theocratic military machine was unleashed on the galaxy. The Entat were merely the first to fall. Race after race were conquered, the Trade Coalition forcibly disbanded while the whole galaxy watched, until, of the population of known space, sixty to seventy percent were under the yoke of the Holy Empire of Hexamar. Crimes against sentients were committed of all kinds, most infamously forced cyborging and brain uploading of conquered peoples. Then, after a long struggle with the nascent Barsamen Confederacy, the Empire finally fell.
Now, half a millennium on, the Theocracy is far weaker, with only four garden worlds to its name. Riven with internal divisions, still struggling with guilt and self-loathing and revanchism and, over the centuries, a number of civil wars, the future still looks very uncertain for those who once came close to ruling all of known space.
THE AAMANTHORAT
There are many strange species, to humans, in the galaxy. Psychology, evolutionary strategies, culture, all are different. And yet, without a doubt, the Aamanthorat are the strangest; petro-metallic beings whose control over their own internal chemical reactions and shape allows them to band together, hundreds or even thousands of individual Aamanthorat donating their mass to build vast ships (that look in their inert form like giant asteroids) to explore the galaxy. With a mindset remarkably communal, and only possessing individual bodies when it is necessary, invading an Aamanthorat planet on foot is a bad idea, as the Hexamari were to learn. Relatively inward-looking, they are potentially far more dangerous than they might seem at first, yet ultimately their interests don't go towards conquest or expansion, and they tend to deal fairly and simply--they have no need for currency, and trade by bartering, quite self-sufficient in most ways--with any and all species they encounter. They are surely the strangest of this galaxy's inhabitants!
THE XVORZIT HIVES
The Xvorzit race's willingness to spread out into individual hives has taken it many places. At times it has been a weakness, at others a strength, and this lack of bias has even led one Xvorzit world to join the Barsamen Confederacy. An intelligent and empathetic species, they have areas in which they are clustered, and yet ultimately they have spread out, here and there, across much of the known galaxy. Despite, or perhaps because of, their lack of centralized power and authority, they are the most numerous species in the galaxy, ahead of both the Barsa and Humans. Individual worlds have their politics and their squabbles, and yet the species as a whole lives on and builds, working always towards a more perfect hive, towards a better world, as it were.
They are a middling-to-strong economic power that does plenty of trade in industrial goods wherever they are. Individual Xvorzit, despite some cultural and social issues with being alone (not a comforting thing for a species that first evolved from bug-like creatures hunted by larger animals that banded together to survive), can be found across the entire galaxy, generally following that old human maxim: "The law of the land is the law."
THE RORROX ASSOCIATION
The Rorrox are the oldest spacefaring race still extant, within known space at least- they first slipped the surly bonds of realspace over twelve hundred years ago- 1143 CE, by human reckoning. Rorrox, much like the Xvorzit, are spread out across known space, mainly because their idea of a habitable world is wildly different to everyone else's, save maybe the Aamanthorat. The Rorrox are more crustacean in appearance than anything else- their homeworld is immensely cold, and the atmosphere thin- as a result, they must don encounter suits when venturing into environments that other races are more suited to. As a result of having no centralized territory, with their worlds quietly existing within areas of space claimed by other races, the Rorrox Association has spent most of galactic history being one of the foremost mercantile powers, though they have never enjoyed uncontested dominance in the same way that the Republic of Sol does now- first the Entat, then the Mercantile Republic offered stiff competition, and now Sol has almost entirely overshadowed them. Still, that hasn't dissuaded the Rorrox at all- the race as a whole keep on plying their trade as merchants and go-betweens.