<P> In October of 331 BC, Darius III, the last Achaemenid king of the Persian Empire, was defeated by the forces of the Ancient Macedonian Greek ruler Alexander the Great at the Battle of Gaugamela . A native account of this invasion notes a ruling by Alexander not to enter the homes of its inhabitants . </P> <P> Under Alexander, Babylon again flourished as a center of learning and commerce . However, following Alexander's death in 323 BC in the palace of Nebuchadnezzar, his empire was divided amongst his generals, the Diadochi, and decades of fighting soon began . The constant turmoil virtually emptied the city of Babylon . A tablet dated 275 BC states that the inhabitants of Babylon were transported to Seleucia, where a palace and a temple (Esagila) were built . With this deportation, Babylon became insignificant as a city, although more than a century later, sacrifices were still performed in its old sanctuary . </P> <P> Under the Parthian and Sassanid Empires, Babylon (like Assyria) became a province of these Persian Empires for nine centuries, until after AD 650 . It maintained its own culture and people, who spoke varieties of Aramaic, and who continued to refer to their homeland as Babylon . Examples of their culture are found in the Babylonian Talmud, the Gnostic Mandaean religion, Eastern Rite Christianity and the religion of the prophet Mani . Christianity was introduced to Mesopotamia in the 1st and 2nd centuries AD, and Babylon was the seat of a Bishop of the Church of the East until well after the Arab / Islamic conquest . </P> <P> In the mid-7th century, Mesopotamia was invaded and settled by the expanding Muslim Empire, and a period of Islamization followed . Babylon was dissolved as a province and Aramaic and Church of the East Christianity eventually became marginalized . Ibn Hauqal mentions a small village called Babel in the tenth century; subsequent travelers describe only ruins . </P>

Where is the city of babylon located and why is it important