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 to the notion of an "inhabited Earth," surrounded by the Ocean, and an "uninhabited Earth" (though exactly how much of this was understood by his student Alexander the Great is not known). "Surah Al-Kahf" has also been linked to the "Alexander romance" through a second story. The Quran verses 18:60–82, which immediately precede the story of Dhul-Qarnayn, mention the story of Al-Khidir and a fish that miraculously comes to life. It has been theorized that the Quran's story was influenced by the story of the Water of Life (Fountain of Youth) mentioned in Eastern versions of the "Alexander romance". In