Answer:
Read below
Step-by-step explanation:
1: Barbarians kept on attacking
2: Internal stability like the killing of Julis Ceaser
3: Ethnic groups inside the Roman Empire that wanted to be free
4: People were hungry for power
5: Failing economic system
6: The Roman Empire being split in two
7: Some people didn't want to change there religion
8: Rise Of Islam ( later years )
9: Different cultures