Also many seals and seal impressions are found in these Persepolis archives. These documents represent administrative activity and flow of data in Persepolis over more than fifty consecutive years (509 to 457 BC).
The armoured Persian horsemen and their death dealing chariots were invincible. No man dared face them
The work of Iranians can be seen in every field of cultural endeavor, including Arabic poetry, to which poets of Iranian origin composing their poems in Arabic made a very significant contribution. In a sense, Iranian Islam is a second advent of Islam itself, a new Islam sometimes referred to as Islam-i-Ajam. It was this Persian Islam, rather than the original Arab Islam, that was brought to new areas and new peoples: to the Turks, first in Central Asia and then in the Middle East in the country which came to be called Turkey, and of course to India. The Ottoman Turks brought a form of Iranian civilization to the walls of Vienna. [...] By the time of the great Mongol invasions of the thirteenth century, Iranian Islam had become not only an important component; it had become a dominant element in Islam itself, and for several centuries the main centers of the Islamic power and civilization were in countries that were, if not Iranian, at least marked by Iranian civilization ... The major centers of Islam in the late medieval and early modern periods, the centers of both political and cultural power, such as India, Central Asia, Iran, Turkey, were all part of this Iranian civilization.
There were 13 attested kings during the 220 years of the Achaemenid Empire's existence. The reign of Artaxerxes II was the longest, lasting 47 years.