Persian.
King of Kings.
Can you show some pictures of Persian Technology and Innovations
The Persian and Mesopotamian kings and the Roman Emperors were all absolute rulers.
Darius and Xerxes.
A monarchy.
They did.
The Achaemenid kings. See the Website below.
Succession.
Their kings and councils.
The commanders appointed by the Persian kings and by the Greek city-states.
There were several Persian leaders called Darius - they were kings of Persia.