Antioch on the Orontes was an ancient city on the eastern side of the Orontes River. Its ruins lie near the modern city of Antakya, Turkey. Founded near the end of the 4th century BC by Seleucus I Nicator, one of Alexander the Great's generals, Antioch's geographic, military and economic location, particularly the spice trade, the Silk Road, the Persian Royal Road, benefited its occupants, and eventually it rivaled Alexandria as the chief city of the Near East and as the main center of Hellenistic Judaism at the end of the Second Temple period. As a result of its longevity and the pivotal role it played in the emergence of both Hellenistic Judaism and Early Christianity, Antioch was called "the cradle of Christianity. " It was one of the four cities of the Syrian tetrapolis. Its residents are known as Antiochenes. Once a great metropolis of half a million people, it declined to insignificance during the Middle Ages because of repeated earthquakes, the Crusaders' invasions, and a change in trade routes following the Mongol conquests, which then no longer passed through Antioch from the far east.