Answer: The Greek and Persian Achaemenid Empires coexisted during 553-336 B.C.E. These two empires had been rivals for centuries, which eventually led to the Persian Wars, happening from 490-480 B.C.E. The Persian Empire was made up of a variety of religions, however the one practiced by the native Persians was focused on a main god, Ahura mazda. The Persian religion was “...centered on an elaborate cult of kingship…” and these kings were believed to have a connection to Ahura mazda. In contrast, the Greek people had the same gods and religion throughout their empire, which were present not only in myth and stories, but also in daily life.