What is "dhul-qarnayn"

n. (context Islam English) The ruler who built the wall that keeps Gog and Magog from attacking mankind.

Dhul-Qarnayn, ( , ), or Zulqarnayn, "he of the two horns", appears in Surah 18 verses 83-101 of the Qur'an as a figure empowered by Allah to erect a wall between mankind and Gog and Magog, the representation of chaos. In the Islamic apocalyptic tradition the end of the world would be preceded by the release of Gog and Magog from behind the wall, and their destruction by God in a single night would usher in the Day of Resurrection. In traditional scholarship the character is usually identified as Alexander the Great, who is ascribed similar adventures in the Alexander romance.