After the fall of the Roman Empire, cities all along the Empire got vulnerable to the Barbaric invasions without the Roman Army to protect them.
Because of the fear of the unknown barbarians feudalism started to develop. The cities started to be protected from invasions inside thick walls, people lived inside those cities that were owned by noblemen and worked to gain protection.
Feudalism shaped the new European civilization making new social classes and shaped a new culture that was more centered around the church and was closed to discoveries and because of that this period is known as dark ages.
