The story of Dhul-Qarnayn (in Arabic ذو القرنين, literally “The Two-Horned One”, also transliterated as Zul-Qarnain or Zulqarnain) is found in the 18th Surah of the Qur’an, al-Kahf (the Cave). While he is never mentioned explicitly by name, the story is clearly based upon a legendary account of Alexander the Great. For centuries, most Muslim historians and Qur’anic commentators endorsed the identity of Dhul-Qarnayn as Alexander, though some also proposed alternatives. In recent years, this identification of Dhul-Qarnayn has become particularly problematic and controversial for Muslim scholars, as historians have gradually discovered that the historical Alexander was a Greek pagan who fashioned himself as a god. This has prompted many apologists to create and advance alternative theories that identify Dhul-Qarnayn as other prominent historical kings, most notably Cyrus the Great. These alternative theories have major deficiencies and fall short of the strong parallels between the Qur’anic story and legends of Alexander that date to the early 7th century.