The term 'Khan IV' refers to the fourth ruler of the Mongol Empire, Genghis Khan. He was born in 1162 and is widely considered one of the most successful military leaders in history. His reign lasted from 1206 to 1227 and he is credited with unifying the Mongol tribes and establishing the largest contiguous empire in history. The term 'AGA' is an acronym for 'Akhoond of the Great Assembly, ' which was a title given to Genghis Khan by his people. This title was bestowed upon him in recognition of his leadership and accomplishments.