ROMAN EMPIRE

Here it is a short explanation on how this empire collapsed.

https://www.zerohedge.com/news/2016-02-19/currency-and-collapse-roman-empire

Read carefully the information carefully and MAKE A CONCEPTUAL BOX including the most relevant details.

This additional page will help you to study more about this empire.

http://www.softschools.com/timelines/roman_empire/timeline_9/