Throughout History, what was the main reason Persia, its relatives fell, and other empires based on modern day Iran's borders and ethnic group, declined, fell and collapsed?
>>3314825
I dont understand your question tbqhwyf
>>3314825
Are you asking why so many Persian empires fell, or why an area that once had powerful empires became what they are today?
>>3314825
Arabs
>>3314825
Steppe people
>>3314830
Oil
>>3314998
Apologize for broken English.
I meant to ask what is the common reason to the collapse of so many Persian empires, not just those, but the relatives of the Persian Empire and other empires that take place in modern day Iran and/or were made of peoples of the same ethnicities of modern day Iran (Sassanids and Timurids, for example)