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
Yu the Great has been dated to about 1920 BCE. This coincides with new cultures all along the Yellow River. The water control problems after the initial flooding could plausibly have lasted for some twenty years. Wu et al. suggest that this supports the idea that the stories of Yu the Great may have originated from a historical person. Yu was long regarded as an ideal ruler and kind of philosopher-king by the ancient Chinese. Beichuan, Wenchuan, and Dujiangyan in Sichuan have all made claims to be his birthplace. Owing to his involvement in China's mythical Great Flood, Yu also came to be