The human controlled galaxy can be a confusing place, but I'm here to help. Trust in me, Mordid, to guide you through the ins and outs of it all.
"Unity, Prosperity, Security"
It was a single, unified government that allowed Earth to expand outside of its solar system. The government offered peace, unity and security in exchange for total obedience. Earth claims to allow freedoms, but, they do so in a way that their experts determine as optimal. To me, it's not freedom they offer, just a gilded cage. You can't even have ideas they don't like.
Religion, for example. On Earth, all religions are the same religion. You can dress up as the pope himself, or as a Muslim, or a Jewish guy, yamaca and all, and it doesn't much matter to Earth Government unless you say anything that upsets their precious unity. That is strictly not allowed. It's also why you wont see many people of Mexican descent on Earth. Actually, you'll have a hard time picking out anyone's ancestry, but more on that later.
When Earth was unifying in the wake of some rather cataclysmic wars that in, all fairness, was caused by greed between nations, not everyone bought in. Most of the big nations were too thoroughly wrecked to oppose the new order, but much to everyone's surprise, Mexico resisted. The point of contention was that, for the first time, a Mexican pope had been elected and part of Earth Government's plan was to control all aspects of everyone's life, including religion.
The pope said, "no", and so Mexico said "no".
The guerrilla war they fought was the stuff of legends and when they knew all hope was lost, they packed it up and left the solar system. Mexicans were some of the first settlers into space beyond the Solar System and they fled as far from Earth as they could get. To this day, they live in a region outside of Earth's control and have a rather dim view of Earth. They were beyond brave. They were the first to use transdrives blind- meaning they leaped out into the void without fully knowing when and where they might appear. Many must have died, but, they eventually made it to a new home ,far, far away.
Back on Earth, I mentioned there was a lack of ancestry. This is part of their unity idealism. One way to achieve unity and harmony is to do away with pesky things like national origins. I even get it. Earth's greatest wars were fueled in part by nationalism, and so, having a single people for ALL the people makes sense.
Being science minded, Earth Government has been selectively breeding people to make better people. People who are resistant to the sun, who won't ever go bald, who will be fit and trim and beautiful. The program has been going on for over a century, and a good portion of Earth's population share the mocha skin, perfect face, and perfect bodies that make a perfect man or woman. This is all great and good if you're a product of that selective breeding, but not everyone is, and not everyone turns out quite the way Earth Government would like. They say they don't judge, but believe me, Earth judges everyone all the time even when they sleep.
After unification, Earth began to take on space travel in earnest. Their Mexicans had already wandered off, nearly blind, into the galaxy, and they followed after them, but in a different way. Earth's progress was slow and methodical. Even before the Mexicans left, Earth Government had been reaching out into the stars, but mostly to survey, plan and prepare for the future. Expansion was not quite the right word for what they did, but more of a slow-moving mudslide of growth.
Earth Government, despite its claims of being peace-loving was born out of a war, fought a war to establish itself and was the first of humanity to encounter and fight alien species. The wars were thankfully quick and brutal, and an uneasy peace lies along their borders. I don't actually know too much about who they fought, how it went down and how things are now. That's the sort of history Earth has done a good job suppressing and I've never been close enough to the borders out there to say much other than I suppose horrid monsters dwell close to Earth.
Earth Government has grand plans. They want to fill the galaxy with like-minded souls, but, were not doing a great job at it. Though no lovers of the free-market, the experts of Earth had an idea. What if capitalism could be chained and then allowed to run just a bit so as to colonize more territory.
The problem with letting a little bit of freedom is that it often leads to someone wanting a lot of it.
"A Fair Deal"
Earth allowed some corporations to be given the leeway to leave Earth Space and colonize on their own. This was called the Corporate Charter which in essence said, "Go colonize, go get rich, but remember who you serve."
It was a naive idea. You can't trust Corpys. I should know, I've worked for, been betrayed by, and betrayed, my fair share of them.
The Corporate Worlds had already existed before Earth gave them permission to exist. Just as the Mexicans had left Earth and taken to looking for a new home, other enterprising sorts followed suit. Now, these folks didn't want a complete break with Earth, just a little freedom.
When the Corporate Charter was agreed upon, Earth ceded its expansion to private interests. Space travel and the transdrive technology became more readily available and the number of ships being produced increased and the number of planets being colonized doubled, then tripled, until finally Corporate Space had swelled to be about the same size as Earth Space, and had done it in a far shorter span of time.
Problems occurred as disputes between the vast companies arose. Technically, the court on New Delhi back on Earth is supposed to handle all such issues, but the reality is, the law is only one tool of the Corporate Worlds. Warfare was inevitable and I'm glad for it.
Aliens don't make it easier. There are very few within the Corporate Worlds, but, some primitive species are in their domain and a dead alien empire is a hot-spot for corporations who want access to illegal, dangerous, alien-tech. Even I don't like messing with that stuff, and I'm terrible!
At first, and this was in the days of my great-grandfather, the companies engaged in low-intensity, often clandestine wars. However, as Earth Government failed to enforce its legal rulings or punish unruly corporations, it became clear that there was no need to hide.
Now, the Corporate Worlds don't like open warfare, and they prefer small engagements, but, if the profit incentive is enough they're willing to send out armadas of ships bearing their corporate logos and colors. Remember that dead alien empire I mentioned? Five corporate militaries and a host of mercenaries are fighting over it.
Life in the Corporate Worlds, I imagine, is slightly more bearable than on Earth. In Earth Space, you can't spit on a wall without being fined, and I'm pretty sure giving someone a dirty look will result in mandatory classes on proper etiquette and good citizenship. In the Corporate Worlds, you're not free either, but you can at least rise to the top.
Everyone in the Corporate Worlds is connected to a corporation, and the big ones are like their own nationalities. There have been generations of people born and raised within a single corporate structure. All the evils of capitalism Earth warns about is happening on a massive scale, all thanks to them. I appreciate the irony even if they don't. Not that there is much they can do about it.
The Upper Arm
The Mexicans were the first to settle in what is called the Upper Arm, because on a galactic map it sort of fills out some of the spiral arm humanity lives within. I'm sure on a celestial scale the name isn't proper, but that's what it is called.
After the Mexicans came, more arrived. Dissidents, political refugees, and madmen, all streamed into the Upper Arm to carve out their own lives. The Upper Arm has no law. Corporations, despots, republics, and pirates all dwell within the Upper Arm bound by only the very loosest concept of, "leave me alone".
I've lived and worked in the Upper Arm all my life and I can't rightly tell you how big it is. The maps do not do it justice because for every translane and system linked up and mapped out, there are dozens of others that go unrecorded. Earth Space is big, but has relatively few settled worlds, and Corporate Space is the same size, but has many more settled planets, while the Upper Arm's size is unknowable. BIG, is all I can say. I know the farthest one can get from Earth is the planet, End Road, populated by inbred monstrous men and women who make fine mercenaries, but dangerous neighbors.
Earth has its aliens, and we have ours. Ours, I've seen, ranging from ship-sized terrors who leave us be, to arachnid beings that want to eat everyone even each other. Mercenaries have been employed to keep the gross, alien menaces at bay and the pay is good, but the work is demoralizing.
Speaking of mercenaries, that's what I am. I sell my services and that of my fleet and army to the highest bidder. The Corporate Worlds actively play their games in the Upper Arm as do plenty of other entities and I'm willing to work for any of them. The Upper Arm produces quite a few mercenaries and the business has never been better. There are countless wars, escorts, raids, and planetary defenses and invasions to be done for a bit of cash.
There are some who say the mercenary forces have spiraled out of control, bringing endless war and disruption to the Upper Arm and the Corporate Worlds, but I disagree. War between professionals might be dirty, but, there's no hard feelings. It's not personal after all, it's business.
Besides, we don't start wars, we just fight them and it's not my fault that the work is plentiful. I blame that on man's nature and the fact that despite Earth's promises, no one can control the human spirit. Sure, we're murderous, but here in the Upper Arm we also have our messy freedom, to do, think, and act as we want. I mean, so long as we don't get killed by someone else. I'm not too worried about that though, I command one of the largest mercenary companies in the galaxy. So, if you're in need, you have the money, and you like spectacular uniforms, be sure to contact Mordid, the Traveling Tyrant.