Western Europe was split into small kingdoms during the Middle Ages. This was a period of European isolation from the rest of the world directly after the collapse of the Roman Empire. Small tribes established their own kingdoms (or even empires). Kings eventually came into play where they established power over a large area, splitting their area into small slices for nobles to rule over. Knights were then protectors of the land, and ordinary citizens and even slaves/serfs lived on the land as well. A kingdom was basically a small, functioning country.
Europe broke into smaller kingdoms from 235-550 AC. Hope this answers your question, though I'm not 100% sure whether or not it's correct.
Much of Western Europe, perhaps half, was in the Roman Empire or West Roman Empire. The rest of it was in tribal lands and small kingdoms.
When the fastest form of communication is a messenger on horseback, governments tend not to grow too large. Europe was settled by humans on foot; their governments tended to be pretty local.
muslims
Europe became a patchwork of little areas of mini-kingdoms.
North West Europe
kingdoms
Judea and Israel
small kingdoms
The greatest threat to the kingdoms was from defeat in war. Most of the early kingdoms did not survive, as those that did survive destroyed the others.
The peoples that formed new kingdoms in eastern and central Europe were the Poles, Czechs, Hungarians, Moravians, Croats, Serbs, and the Bulgarians.
how did centralized monarchies develop in Europe
After the fall of Rome what two things caused Western Europe to divide into multiple kingdoms