Iraq was ruled by the indigenous empires, Sumerian, Akkadian, Babylonian, Assyrian and also by foreign empires: Median, Achaemenid, Seleucid, Parthian and Sassanian empires during the Iron Age and Classical Antiquity, before Iraq was conquered by the Muslim Rashidun Caliphate in the 7th century, and became a center of the Islamic Golden Age during the medieval Abbasid Caliphate.