as Dhu al-Qarnayn, traditionally believed to be Alexander the Great, who built a wall made of iron between two mountains to defend the people from Yajuj and Majuj. During the Middle Ages, the Gates of Alexander story was included in travel literature such as the Travels of Marco Polo and the Travels of Sir John Mandeville. The identities of the nations trapped behind the wall are not always consistent, however; Mandeville claims Gog and Magog are really the Ten Lost Tribes of Israel, who will emerge from their prison during the End Times and unite with their fellow Jews to attack the Christians. Polo speaks of Alexander's Iron Gates, but says the Comanians are the ones trapped behind it. He does mention Gog and Magog, however, locating them north of Cathay. Some scholars have taken this as an oblique and confused reference to the Great Wall of China, which he does not mention otherwise. The Gates of Alexander may represent an attempt by Westerners to explain stories from China of a great king building a great wall. Knowledge of Chinese innovations such as the compass and south-pointing chariot is known to have been diffused (and confused) across Eurasian trade routes. The medieval German legend of the Red Jews was partially based on stories of the Gates of Alexander. The legend disappeared before the 17th century. Geographical identifications Medieval In medieval world maps, the land of Gog and Magog is generally shown as a region in the far north, northeast, or east of Asia, enclosed by mountains or fortifications and often featuring a gate. It is depicted in this way on Arabian world maps starting from the 10th century, as also on the Tabula Rogeriana, an influential map drawn in 1154 by Muhammad al-Idrisi for Roger II of Sicily. Modern It is not clear which precise location Josephus meant when he described the Caspian gates. It may have been the Gates of Derbent (lying due east, nearer to Persia), or it may have been the Darial Gorge, lying west, bordering Iberia, located between present-day Ingushetia and Georgia. However, neither of these were within Hyrcania, but lay to the north and west of its boundaries. Another suggestion is some mountain pass in the Taurus-Zagros Mountains, somewhere near Rhaegae, Iran, in the heart of Hyrcania. Derbent The Gates of Alexander are most commonly identified with the Caspian Gates of Derbent, whose thirty north-looking