The European economy of the Middle Ages was nothing compared to that of the Roman era. However, there was a significant improvement and strengthening of religious bodies after the fall of Rome. At first, Christianity was banned in Rome, and Christians were persecuted by many emperors such as Nero.
After the Roman empire's collapse, ethnic chiefs and kings, ex-Roman governors, generals, warlords, peasant leaders, and bandits carved up the former Roman provinces into feudal kingdoms. The Visigoth kingdoms of Spain (from 419) and France (from 507) retained Roman administration and law.
After the Romans left Britain, there was a great spread of Angles, Saxons, and Franks, with minor rulers. It is thought a duo of prominent rulers named Horsa and Hengist came to power. There was also a Saxon king, who is traced to all royalty in Britain and known as Cerdic.
The fall of Rome also paved the way for another major part of Europe's history: feudalism. When Rome fell, Europe fell into a state of constant warfare. The new kings wanted to tax their populous and wanted them to fight during times of war. This practice was, of course, unpopular.
The new kings allowed the landowners to raise their small armies that the kings could call upon to defend the kingdom. This system provided local protection from anyone who might want to pillage the land, such as the Vikings or Magyars. This eventually developed into the system of feudalism that dominated medieval Europe
Feudalism helped prevent another strong centralized government, like that of Rome, from forming in Europe for hundreds of years. Although landowners swore loyalty to the king, they would further subdivide and distribute their lands to people who swore loyalty to them. Naturally, this created a decentralized government that was prone to internal conflict. Feudalism also further weakened trade and economic development in Europe.
Serfs who worked the land were bound to the land and forbidden to create economic infrastructure without their lord's permission. Since serfs had to pay taxes and tolls to use their lord's infrastructure and resources, it was not in their lord's best interest to give them the privilege to develop the land.