Long, long ago, during the sixth century B.C. King Dhul Qurnayn ruled the lands from the Aegean Sea to the Indus River. He was just and righteous, protecting the weak and punishing the law-breakers. When he took his armies to the North East of Iran, he reached the Caucasus mountain range which runs between the Caspian and the Black Seas.
Once, in that region, he met a tribe who begged him to protect them from the wild tribes, the Yajuj and the Majuj (Gog and Magog) who kept coming through the mountain passes, and attacking them. dhul Qurnayn asked for iron blocks and molten brass and, with the help of the local people, he built a barrier across the valley to hold back the Yajuj and Majuj. After conquering a major part of the then inhabited world Dhul Qurnayn had lost none of his humility. He gave the entire credit for his feats to the blessing of Allah. Of the iron wall he had built, he said: “This is a blassing from my Lord. But when my Lord’s promise has been fulfilled, He will level it to dust. And the promise of my Lord is true.”