Dhul Qarnayn ذو القرنين was mentioned in Quran as a servant of Allah who was granted a strong rule on the earth. Sura Al-Kahf, verses 83 to 98.
He helped people who were suffering from the evil of Gog and Magog and built a huge block of iron and copper to protect the people from the attacks of Gig and Magog.
Wassalam.