Answer:
Rome was able to gain its empire in large part by extending some form of citizenship to many of the people it conquered. Military expansion drove economic development, bringing enslaved people and loot back to Rome, which in turn transformed the city of Rome and Roman culture.
Step-by-step explanation:
Reasons of falling of Rome empire.
Invasions by Barbarian tribes. ...
Economic troubles and overreliance on slave labor.
The rise of the Eastern Empire.
Overexpansion and military overspending.
Government corruption and political instability.