Jews of Medina once asked Prophet Muhammad about a man named Zolqarnein. Verses 82 to 97 of Surah al-Kahf, the 18 th chapter of the holy Qur’an, give description about this king who believed in God and the Day of Judgment. According to these Verses, God provided opportunities for Zolqarnein to be victorious over his enemies and bring justice to the territory under his jurisdiction. These Verses do not mention the place, time, or his name, and Zolqarnein that is his title has been referred as Qarnayeem in Jewish Pentateuch.These uncertain issues have caused many commentators of the Qur'an and Islamic scholars to introduce different individuals as Zolqarnein. Among these, Cyrus, the Achaemenid king and Alexander, the Macedonian king, could be seen more than others. This study aims to determine the character of Zolqarnein, by taking the historical approach. For that matter, religious and historical documents such as the Quran, Torah, Cyrus Charter, and writings of classical Greek historians were studied and corroborated with archaeological evidences. Based on the results of preceding studies, Zolqarnein is found to be Achaemenid king, Cyrus the Great.