Alexander the Great in the Quran called them the Caspian Gates. Twenty and two Kings did I shut up therein. These pseudepigraphic letters from Alexander to his mother Olympias and his tutor Aristotle, describing his marvellous adventures at the end of the World, date back to the original Greek recension α written in the 4th century in Alexandria. The letters are "the literary expression of a living popular tradition" that had been evolving for at least three centuries before the Quran was written. Several historical figures, both Muslim and Christian, searched for Alexander's Gate and several different identifications were made with actual walls. During the Middle
Alexander the Great in the Quran However, it is clear that the historical Alexander the Great was a Greek pagan (for example, Alexander's mother Olympias is said to have been a devout member of the orgiastic snake-worshiping cult of Dionysus, and may have slept with snakes). Such historical facts about Alexander the Great became well known only after the Renaissance period (1300–1600 AD) when the "Anabasis Alexandri" of Arrian (AD 86–160) was rediscovered. In light of the modern view of Alexander the Great, his identity as Dhul-Qarnayn has become a matter of great controversy for Muslims. In reaction, alternative theories about the identity of Dhul-Qarnayn have