ThePersian Empireis any of a series ofimperialdynastiescentered in Persia (nowIran). The first of these was established byCyrus The Greatin 550BC, with the Persian conquest ofMedia,LydiaandBabylonia. Persian dynastic history was interrupted by theIslamic conquest(AD651) and later by theMongol invasion. The main religion of ancient Persia wasZoroastrianism, but after the 7th century this was replaced byIslam. In the modern era, a series of Islamic dynasties ruled Persia independently of the universalCaliphate. Since 1979 Persia (Iran) has been an Islamic republic.List of dynasties Achaemenid Empire(550330BC), also called the "First Persian Empire" Parthian Empire(247BCAD224, also called the "Arsacid Empire" Sasanian Empire(224651), also called the "Neo-Persian Empire" and "Second Persian Empire" Safavid dynasty(15011736) Afsharid dynasty(17361796) Zand dynasty(17501794) Qajar dynasty(17851925) Pahlavi dynasty(19251979)