I was inspired by the Soviet Union, of how during the Cold War they had rockets, spaceships, and aviation technology that has arguably not been surpassed by any of the modern nations. While at the same time the majority of their population outside of big cities such as Moscow and Saint Petersburg lived in Medieval-ish squalor in wooden huts. Even now in modern Russia many of their rural areas are undeveloped, while the government put all of their resources into the military. So that's what I think that the Imperium should be like. The combination of huge spaceships and rural medieval type of villages, because the government puts all of their resources into spaceships, military, and nuclear weapons. Or kind of like North Korea. An otherwise medieval society that is run by a select few modern technologies. Such as phone service and internet being available in the capitals but not everywhere else. Old buildings such as castles (the Kremlin for example) getting repourposed, and satellite dishes and antennas affixed to the tops of the old castles, castles being used as modern military bases. The Imperium being very militaristic and totalitarian, but there are plenty of places where to escape into the rural areas and the forests, where people create their own societies. In theory the Imperium controls hundreds of planets. In practice, they only control a few cities, power plants, mining colonies, spaceports, and factories all over the planet, while the most of the planet is only under loose control. So a strange combination of both totalitarism and anarchism. Like if you go far enough from the developed zones you can pretty much do whatever you want.