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
Kalanos Kalanos Kalanos, also spelled Calanus ( – 323 BCE) was a gymnosophist (literally "naked philosopher"), a philosopher from Taxila who accompanied Alexander the Great to Persis and later committed suicide by self-immolation. It was from Kalanos that Alexander came to know of Dandamis, the leader of their group, whom Alexander later went to meet in the forest. Plutarch indicates his real name was Sphínēs and that he was from Taxila, but since he greeted people with the word "Kalē!" - perhaps "kallāṇa (mitta)" "Greetings (friend)" - the Greeks called him Kalanos. Kalanos lived at Taxila and led an austere life.