Religion in the Achaemenid Empire
Religion in the Achaemenid Empire (Persian: دین در دوران هخامنشی ), continues to be a source of debate among academics. The available knowledge about the religious orientation of many of the early Achaemenid kings is incomplete, and the issue of Zoroastrianism of the Achaemenids has been a very controversial issue.
Source: Wikipedia — Religion in the Achaemenid Empire (CC BY-SA 4.0)