About Yazd The city has a history of over 3,000 years, dating back to the time of the Median empire, when it was known as Ysatis (or Issatis). The present city name has however been derived from Yazdegerd I, a Sassanid ruler. The city was definitely a Zoroastrian centre during Sassanid times. After the Arab Islamic conquest of Persia, many Zoroastrians fled to Yazd from neighbouring provinces. By paying a levy, Yazd remained Zoroastrian even after its conquest, and Islam only gradually became the dominant religion in the city.