The Sassanids were also great in trade and culture.
After the Moslem conquering and then Timur-i-lang's massacres Iran didn't fluorish until the 16th century and then was under threat from the Turks, the Mughals and the Russians.
Sorry, I might not have made myself clear...I meant everything went downhill after the celebration of 2500 years of the history of Persia.
Thanks to the assistance of the United States of America.
Carter should have kept his nose out of it.
Islam happened