After the fall of the western roman empire, what filled the void left by the disintegration of the political structure?

 After the fall of the Western Roman Empire was the Dark Age its also called  the Middle Ages or the Medieval period which was from the 5th to the 15th century.
Here is a set of flash cards from quizlet if you have any more questions about the western romans fall.
https://quizlet.com/133251347/the-fall-of-the-roman-empire-flash-cards/