Article 3: Nekopotamia
Before the Golden Alliance was formed, spacefaring civilizations were considered extremely rare. Most of them consisted of pre-biowarp or limited-warp tech like that the Uruseiyans developed, and thus in such cases only ever went as far as neighboring star systems. The Watchers and early Angelic Protectorate provide examples to the contrary, but even with each having a massive sphere of influence in their own way, none seem to have been spread as far across the galaxy as the ancient Nekopotamian civilization. From Elemental League to GAN space, planets have been found harboring relics and legendary tales about the great Nekopotamian Empire and its ruler, the Princess Kasumi. Though it's very widespread, there's often very little trace of what the Nekopotamians actually were. In addition, though it's been theorized that the Watchers possess more information and may have even coexisted with them, they've never given up any information about them. Despite these hurdles, through centuries of dedicated study, intragalactic archaeologists have pieced together a few details about the mysterious civilization that are treated as fact by the Castaways Treaty Systems. In addition, scattered recovered memories from Princess Kasumi herself help to make MSF High students' understanding of the Nekopotamians by far the most complete.
Based on the data we have, the Nekopotamian civilization began on the planet that we now call Purraxia(previously Ilithar by GA records). We can surmise this based on both the more extensive sets of artifacts found as well as its apparent place as the seat of power for the Nekopotamian people. Their spacefaring reign seems to span a time period ranging from approximately 15,000 BC to 11,000 BC, but their culture is far older than that. According to their writings, it was not until Princess Kasumi appeared at around 15,000 BC that the Empire was formalized. Some historians consider Kasumi to most likely be a Life Elemental, one of the earliest recorded sightings of one in the galaxy, as she brought with her the technology to bring the catlike Nekopotamian people into space as well as what the writings refer to as the Mother Ship, a vessel that is described as being impossibly huge and possessing technology that hastened the fostering of life on other planets. Nekopotamians described themselves as the custodians to new life, and it's widely believed that they took it upon themselves to care for planets that had been touched by the Mother Ship, helping safeguard the accelerated evolutionary processes that gave rise to many modern races.
Side Note: It's often asked by those who are not Scholars of history why Kasumi chose the title of Princess, rather than Queen or Empress, as would be more befitting the ruler of a stellar empire. Based on Nekopotamian teachings and confirmed by Kasumi herself, she did so because she believed the galaxy itself to be a sentient and lifegiving power, though on a level completely above her own. Thus, she felt that in performing her duty to fulfil the galaxy's will by seeding it with life, she could not claim the highest title, instead considering herself a daughter of the galaxy itself.
Kasumi's Mother Ship took an approach that many might consider the opposite of traditional terraforming: Instead of tailoring a planet to fit a specific lifeform, it helped life blossom that was adapted to the planet it would someday hopefully be able to understand as home. While other civilizations in the galaxy have pre-spaceflight histories that extend past the known dates of the Nekopotamian civilization, none have any recorded contact with them, implying that they may have had a policy of non-contact with sentient beings very similar to the Watcher Protection edicts. Unfortunately, as their process was one of evolution and therefore speciation, it's impossible to say with total certainty which races may have been brought into being thanks to the Nekopotamians, but modern Demi-humans say that most human variations, divine, and by extension Devilings should all consider the Nekopotamians their progenitors as most civilization timelines tend to start at around the same time the Nekopotamians were seeding planets with life.
Unfortunately, right before the emergence of the Golden Alliance, all traces of them save the occasional artifact seem to have disappeared. Not even Kasumi knows for sure why the Empire vanished seemingly overnight, but the general Demi-Human consensus is that once her duty was completed, the original Princess Kasumi finally died and was reunited with the Galaxy, while her Nekopotamian followers all boarded the Mother Ship and took off to seed another galaxy with life. However, this is not where the story ends. As most with even a passing knowledge of galactic history are aware, the Golden Alliance found an actual trace of Kasumi's remains in the form of a lock of perfectly-preserved emerald-colored hair. Using advanced DNA scanning equipment, the scientists were able to resurrect the Princess in a cloned body, and this body became the point of contention for numerous political and even religious groups. Samples of her DNA were used to find a way to splice Human and Animal DNA and create the first Demi-Humans, while her body itself never actually woke up until its arrival at MSF High. Though the body itself is no longer in the possession of any one political group(unless you count Kasumi herself as one), there are still ongoing military operations, mostly between the Golden Alliance and the Castaways Treaty Systems, as to who should be the ones to collect the body once it turns up as well as squabbling over other Nekopotamain artifacts, which are a popular target of CTS reclaimer squads such as the one first-year student Nanako was part of. In addition, the majority of CTS citizens, especially those of Demi-human descent, are poised at the ready to rename their faction the New Nekopotamian Empire if Kasumi even re-emerges.(Of course, many have tried to claim to be her in some form or fashion, but all of them have been rejected on the criteria that Demi-Humans will all know the real Kasumi when they see her.)
In summation, not very much is known specifically about Kasumi's past or the life-seeding Empire she ruled, but all indications point to it having been a force for great good in the galaxy. Her presence at MSF High and the inspiration she provides through her historical exploits to those in the outside galaxy, while a source of conflict for some, provides hope and an excellent role model for others. How the galaxy will react when she finally decides to re-emerge is another mystery that we will someday learn the answer to.