Ibn Khaldun was a 14th century Tunisian historian who straight up invented sociology in the 1300s, four hundred years before Auguste Comte got himself a Wikipedia page for it. The guy wrote The Muqaddimah (that’s “Introduction to History” for you non-Arabic speakers) and it is still worth reading today. Six hundred year shelf life. Not bad for a book written before the printing press.
asabiyyah (social cohesion). Basically, civilizations rise and fall based on how tight-knit their people are. Nomads have killer asabiyyah because they need each other to not die in the desert. So they conquer the soft city dwellers, become the new elite, get fat and lazy, lose their cohesion, and then the next hungry nomad gang rolls in and takes over. The wheel keeps spinning. It never stops.
This explains basically everything. The Mongols conquered half the planet because they had asabiyyah out the ass. Rome fell because rich Romans stopped giving a shit about the republic. Every empire follows the pattern. The United States? Yeah we are probably in the decadent phase right now. Ibn Khaldun called it from the grave.
He was also the first guy to treat history like a science. He said: question your sources, look for patterns, think about economics. This was the 1300s. Europe was still arguing about angels on pinheads.
Starter book: The Muqaddimah (1377). It is long but you do not need to read the whole thing. Read the introduction and the first two chapters. That is enough to get the framework.