Many thousands of years ago the only space faring race in our local star cluster were the dragons. Not the mindless brutes of European myth but rather the wise and thoughtful nature spirits of Asian myth. Back then the only way to travel between the stars was by brute force. Generational ships were the first to visit other stars. Once they arrived at a planet they tended to have to stay there. Later came immense tunneling portal devices creating massive wormholes over interstellar distances and using prodigious amounts of energy. These dragons are the reason that the other alien races (Humans, Avinites, Raptillians(Though they don't really keep track of history.), Leonines and Insectoids) have myths about these types of dragons.
The Dragons eventually created a better way to reach the stars. Great rings of solar energy collectors were built to feed off the energy of the star they encircled. This massive amount of energy collected was used to put massive permanent bends in space. These bends were not active portals but merely assisted in portal creation. These devices were entirely stealthed and could only be detected by portal technology and only then by being at one end or the other of the designated transfer points. As they were typically set up; you would have a star in the middle for collecting energy and a star on either side as the destination points to travel to or from.
If the destination stars had planets orbiting them; the point at which you could create a portal was typically put away from the the planetary orbit(s). Earth for example only has one portal creation point leading to a single other system. This point is twice the distance that the earth is from from the sun and, if you think of the solar system as a disc lying on the floor, it is above the disc. There are many of these devices in our local star cluster and as a whole they form the bookmark network. Each bookmark device being a two way street between two specific destinations. Some stars, like our sun, have only one way out like a culd-de-sac. Some have two, like a highway. Other have three or more, like a hub.
Now we come forward many thousands of years. A little less than a hundred years ago a race that will later be named by Humans as the Leonines discovered the bookmark network. Unlike ours, their star system had three bookmarks. One of these three led to another solar system. This solar system, in addition to being amazingly close, had an even more amazing thing on it. Sentient life. This was the home world of the alien race the Humans eventually named the Raptillians. The Raptillians, like the Leonines, had developed super powers. Through quite a bit of social Darwinism the Raptillians had bred true quite a large number of these powers. Unfortunately their culture was strictly hunter/gatherer as they lacked the ability to cooperate to any significant level.
It was clear to the Leonines that the Raptillians could never develop technology on their own. They were not, however, unintelligent. They could learn technology they simply had no infrastructure with which to develop it over time. The Leonines on the other hand were a very industrial society. They had developed their own fossil fuel powered rocket ships. They had invented lasers and portals. They had quite a lot of skill at creating new materials with which to build things as well. They hadn't quite gotten to the point were they could create sentient freemorphs yet but they would later be known for it. As such they felt it was their duty to uplift the Raptillians from their savage lives with the power of science.
The Leonines began teaching science to the Raptillians on a massive scale. Quite a few of them proved to be well capable of understanding and reproducing the concepts behind rocket ships and internal combustion engines and gunpowder weapons. Some of the more advanced technology on the other hand such as lasers and portal generators were simply black boxes to them. They could work them with ease and even repair them, but they were not yet capable of creating them from scratch. The Raptillians began building ships of their own complete with on board manufacturing facilities and jungles for food and air. They even had Portal generator engines provided by the Leonines so that they could explore the bookmark network. The Leonines were immensely proud that they could bring their neighbor species so far in so short a time frame.
Then, of course, things began to go south. The Raptillians bit the paw that fed them. they were now space faring in large numbers but they were not yet satisfied. Many of the smarter ones wanted to learn the secrets of the more advanced technologies. The Leonines, of course, continued to teach these. Many others, however, wanted to pillage and loot. They began boarding Leonine ships to raid them of supplies. There even began to be many attacks on the Leonine home world itself. The Leonine populace was outraged at this. Unable to reason with the enemy they attempted to fight as Leonines have always fought; They tried to knock out the leadership. Unfortunately Raptillians have no root leadership. A Raptillian will rarely personally know more than 30 people in their entire life and a Raptillian never trusts anyone they don't know personally.
As the wars waged on the Leonines grew more desperate. If they couldn't knock out a group of people to stop the Raptillians then they only had one option left. They did the unthinkable and torched the Raptillian home planet. They rendered it unsuitable for life and killed all the life currently on the planet. The Raptillians, however, were not stopped by this. Many of them remained, now as nomads in space. Without a home planet to return to they redoubled their raids on leonine ships and the leonine home planet. Those who survived were only the roughest and toughest of pirates and other scum. Soon they began to spread even further into the bookmark network. They became an ever present scourge on the rest of our local star cluster. The Leonines have to deal with them on a regular basis.
Roughly 70 years ago the Raptillians discovered a new planet full of life. Many of them landed there. Not having had a planet of their own for many years; several of the Raptillians attempted to settle this planet and make it their own. There was just one problem. This planet already had a sentient species. The planet was small with lower gravity and as such had massive land animals even bigger than the wooly mammoth. It also had enormous birds. One such species of birds was sentient. This was the species that Humans would name the Avinites. They had a feudal governmental system and unlike the Raptillians had managed to unite their entire species under a single Empire. They revered super powers and thought them to be magical in nature.
Needless to say the Avinites did not appreciate the Raptilian presence on their planet. They found them needlessly destructive to nature and violent. The Raptillians, however, had already begun to breed like crazy. It wasn't long before the Avinites had to act to stop them or face their own destruction. While the Avinites didn't have the advanced technology that the Raptillians had gotten from the Leonines, or their brutish fighting skill, they did have something the Raptillians did not. They could cooperate. They had organization and regimentation. They could form groups of many with the same power to achieve amazingly massive effects. They fought long and hard to get the Raptillians to leave or die. Many of them did leave, many of them died. Many Avinites also died. Eventually they managed to sequester the Raptillians to one continent while the Avinites continued to live on another.
In the course of these battles the Avinites managed to wrest the secrets of space travel from the Raptillians through torture and theft. Having captured many still functional ships and able to repair others they put together a fleet. The fleet consisted entirely of winged designs because the Avinites believed that things without wings should never fly. It was for this reason that the remaining Raptillians on their planet tend to wander the land or live on boats. The Avinites heavily enforce the ban on Raptillian flight. With the ships they now had the Avinites became a space faring race. Unwilling to wander space alone they formed a fleet of the ships they had. The Fleet went everywhere in space as a group, never straying from the flock. It wasn't too long after this that the Avinites discovered the bookmark system.
The Raptillians of course didn't all settle on the Avinite home world. Oh no. They littered our local star cluster and were found just about everywhere. It was a little over 50 years ago that they found Earth. Our Earth. They didn't get at all what they were expecting in this case. Humanity had neither the separation of the Raptillians nor the union of the Avinites. It was used to fighting wars where both sides formed massive groupings. In fact it had just finished up with the most massive such war ever to be fought; World War II. The majority of the Raptillian ships were shot right out of the sky. Most of those that managed to land were destroyed afterwards in viscous battles. It was because of this that Humanity never got its hands on the secret of the bookmark system.
However, this was not the end of the Raptillians on Earth. The Humans, while warlike, were also caring. They raised the young of the slain Raptillians as their own. These Raptillians grew up being taught Human ideals and being integrated into Human society. There still remained some rogue Raptillians in the distant jungles but the majority on earth had been entirely humanized. These humanized Raptillians were often still violent and tended towards street gangs and things of that nature but others had become quite civilized. While most Raptillians are raised by other Raptillians these days they have been indoctrinated for generations and tend to raise their young in a similar manner to the way Humans do.
While I said the Humans never discovered the bookmark network on their own that's not entirely true. A robotic race, derived from Humanity and known as the collective, has. Their leader was once Human but the members of the collective under him are all original AIs. About twenty years ago, in an experiment with advanced portal technology, they discovered Earth's only bookmark. They followed it and discovered our neighboring star system. This system was not capable of supporting organic life but it was a treasure trove for mining. The Collective moved right in and began setting it up as their primary base of operations. They fancied themselves the guardians of Earth and, as such, fought off the majority of Raptillians in the nearby bookmarks, preventing any more from ever reaching Earth.
Now we pick up where we left off with the Avinite star fleet. They had explored space for a while and almost always found nothing but lifeless planets, empty stars and Raptillians. They tended to avoid the direction that had the most Raptillians, which was the direction of the Raptillian and Leonine home worlds, so they went in the opposite direction instead. Closer to Earth they found fewer Raptillians both because they were farther from the home world and because of the Collective's hand in things. Eventually the fleet found itself in the Collective's own system. The Avinites made peace with the Collective and the Collective consented to allow a single ship of the fleet to fly to earth. The Admiral of the fleet accepted this offer and swore to keep the existence of the Collective a secret from the Humans.
The Humans, of course, spotted the Avinite ship on long approach. However, thanks to the Collective, they had been given a translator (based on what they'd learned from the Raptillians they had fought.) and were able to communicate with the Earth over radio and explain that they came in peace. This ship was allowed to land in New York where the Avinites met with the UN council. The Avinites were shocked and appalled to find, among the Humans, a Raptillian acting as an ambassador. The Raptillian himself, having been raised by Humans, was shocked and appalled at the Avinite's prejudice against him merely because of his species. Eventually the Avinites grudgingly relented.
As a peace offering to the Humans; The Avinites brought forth the best singer from their crew. Oh what a singer she was. The Avinites pride themselves on their singers and this one was particularly good even by their standards. She sang before the UN and was broadcast on live TV all over the world. Unfortunately this caught the eye of a special collector. This was a man who was a hunter in the wilds of Russia and eventually joined the Russian Mafia. Once he got out of the Russian Mafia he came to America and started his own business; illegally breeding and selling super powered animals. He particularly liked birds as pets. Deciding he wanted the singer as his pet he put out a kidnap bounty on her.
When the Avinites returned to their ship in Central Park, they found themselves swarmed with mercenaries. The park became a battleground as many men and women attempted to get their hands on that bird. Luckily the singing Avinite was saved in a daring car chase consisting of no less than three crashes. The Avinites were infuriated with the evil actions of the Humans but were able to see the good in Humanity still. They thanked the heroes who helped to save them and offered to take them back to their home planet for a visit. They also offered the opportunity for grain farmers to come to their planet and create farms. At the same time the Collective found out who put out the reward on the kidnap of the singing bird and went to pay his private zoo a very violent visit.
Meanwhile, back on the Avinite home planet, there has been an upswing in the war between the Avinites and Raptillians. It had died down in recent years but there were still raids by the Raptillians on Avinite settlements. They did they best they could to fight them off and that was that for the most part. Now, however, a Raptillian with delusions of grandeur has decided he wants to unite the Raptillians under himself, as their emperor, and take over the planet. As his first act he united his boat and crew with the boat and crew of another pirate captain. They recently killed one of the Queens of the Avinite Empire. This Queen just so happens to be the mother of the admiral of the ship on earth.