He was an interesting character but the Achaemenid Empire at its peak had approximately 50 million people and that's a lot of people at any time in history but especially at that time in history because at that time in history, there was only a little over 100 million people in the world or at least that's our current estimates so this is actually the largest proportion of the world's population that any empire has ever had in history as far as we can tell so that gives it some claim to being maybe the greatest or one of the greatest empires in world history and then as we get into the Seleucid and especially the Parthian Empire, in the West, we talk a lot about the glory of the Roman Empire but the Parthians were right there beside of them and they kind of went back and forth but they were side by side. The peak of the Parthian Empire coincides with the peak of the Roman Empire and they gave each other space and they went back and forth especially around the Middle East and you have this empire from the Parthians, you go to the Sasanians and eventually in the 7th century CE, you have the Islam comes into the Persian Empire and becomes the dominant religion and so that might make you ask, well, what was the dominant religion before that? And the answer there is Zoroastrianism. Zoroastrianism and it was Zoroastrianism and it was really Cyrus the Great by establishing the Persian Empire who really spreads Zoroastrianism and Zoroastrianism is based on their prophet Zarathustra and when Zarathustra lived is up for some debate. It might be as early as 1500 BCE. Some people say it might be even right before or even coincident with the life of Cyrus the Great and so there's some debate on when Zarathustra lived but it was a monotheistic religion following the one god of Ahura Mazda. Ahura Mazda and it was based on these ideas of good thoughts lead to good words and good deeds.