Google is your best friend until you graduate from college.
The Germanic tribes invaded and ultimately destroyed the Western part of the Roman Empire in the 400s. The invasions took place around 406 BC. The fall of the Western Roman Empire did not happen in a day but it took about a 100 years for the empire to fall. I hope the answer helps you.
Answer:
the first government in the United States was known as "The United States In Congress Assembled"
The crusades used these techniques to spread Islam across the world