Erdan-3 Autonomous Unincorporated Territory.
When first contact occurred in 2024, humans had expected that their first contact would be with a Star Trek-style scout ship. Namely, composed of scientists and explorers from an altruistic and pacifist race that would have nothing but the most peaceful intentions towards other intelligent species that they found beyond the stars.
How wrong they were.
First contact would be with an automated probe from the Cyrania Hegemon, which would enter the solar system and begin scanning for bodies present. The only reason it was detected would be because one of the rockets that were part of That Afrikaner's attempts to travel to Mars would detect it. Naturally, those who received the message on Earth would take it as a mechanical failure (recordings record unflattering comments from ground control about the sobriety of the rocket pilots), so nothing would be done until the probe was detected on approach to Earth.
It was never known if it was the United States or Russia, and it does not matter too much: the fact would be that, as it approached Earth, the probe would be hit and destroyed with anti-satellite weapons. This event would be highly celebrated as a great deed on the part of humanity, as well as a watershed event in which they had saved the human species from "evil aliens". Another hypothesis suggests that the probe was actually shot down because it was mistaken for a spy satellite of a rival nation state.
What the humans did not expect was that, before dying, the probe would have the opportunity to send a distress signal to its home world...
The best that can be said for the subsequent War of Conquest of Erdan by Cyrania is that it was brief. Humanity, which counted the Space Shuttle and the Buran as its greatest achievements in aerospace engineering, and sending people to the Moon as the furthest distance a human being had been sent... was not prepared to face the sudden arrival of heavy fleets of ships of all types and sizes, which would arrive in a matter of weeks thanks to their powerful Phase Jump Engine technology, and the construction of powerful teleportation rings in Lunar Orbit. (Called "Hypergates", "Supergates" or other names, depending on which sci-fi franchise the humans were fans of)
After the dust settled on the graves of billions of humans, the Imperial administration found itself with the unenviable task of managing the mess the humans were making of the planet. Partly because the structure already existed, partly to stick a finger in the eye of the humans who had ignored it when they were still free, it was decided to build a planetary local government using the remnants of the old United Nations.
The Home Rule Government (self-government because it is not considered fully integrated into the Empire) would be given the name the planet had been given on Cyranian maps: "Erdan-3". In contrast to the old UN, the organization is heavily centralized from top to bottom and the "States" are as autonomous as the French provinces could be (virtually nothing). The main reason the "States" structure has been retained was because it was practical, even if larger States have been divided into multiple smaller States for ease of administration.
It is expected that when the minimum standards in science, technology, development and sanitation are reached, the Unincorporated Territory will become directly annexed by the Hegemon, although this is not expected to happen for at least the next 200 years.
(The flag uses the old United Nations emblem in gold on black, a combination more to the liking of the new lords. The blue cross comes from the Russian Navy flag, but using white instead of black. The eight stars come from the flag of the Azores Islands.)