Zoroastrianism

Timeline

1. c. -600–-550Eastern Iranian Plateau · IranCentered on early hymns such as the Gathas, forming exclusive worship of Ahura Mazda, an ethic of choosing between good and evil, and purification rites of fire and water; doctrine was transmitted orally through priestly memory.
2. c. -550–-330Persepolis–Pasargadae area · FarsUnder Achaemenid kings such as Cyrus and Darius, Zoroastrian elements were integrated with imperial cult and royal legitimacy discourse; fire altars and the name 'Ahura Mazda' appear in royal inscriptions, forming an influential Persian religious culture.
3. c. 224–651Ctesiphon–Persian heartland · IraqThe Sasanian dynasty promoted Zoroastrianism as the state religion; the priestly class (mobad) gained power, texts such as the Avesta moved from oral to written form, and doctrines, marriage, and purity laws were further systematized.