I think that the best answer is that they ended up living in areas distinguished by poverty and lack of social mobility, that is lack of the opportunities to improve one's social and economic situation.
Humanism. It was called such way because humanity was put up front and center again, just like in Ancient Rome and Ancient Greece. The tendency of artists and philosophers and writers to talk about things related to church began to dwindle and everyone started focusing on both the physical and psychological appearance of people.
The earlier years of the middle ages began with the fall of the western roman empire.
The main reason is to know which company can have more power