The ancient city of Babylon (or Babel) lay on the left bank of the Euphrates River not far south of the modern city of Baghdad, the capital of Iraq. The term also sometimes refers to the state of Babylonia which surrounded it. Babylon, like Egypt and Assyria, was one of the powerful neighbours of the Israelites in Old Testament times. From 587-539 BC many Jews were held in captivity in Babylon in a period known as The Exile. In 587 BC Nebuchadnezzar, the ruler of Babylon destroyed Jerusalem. Only after his defeat in 539 by Cyrus of Persia were the Jews allowed to return from exile.