Who is Genghis Khan/Temujin from Genghis Khan and the Making of the Modern World and what is their importance?

Temujin was born in 1162 to Yesugui, leader of the Borjigin tribe, and Hoelun, from the Olkhunut tribe, in what is modern day Mongolia near Burkhan Khaldun. The Secret History of the Mongols reports that he was born with a blood clot in his fist. He had three brothers, Khasar, Khajiun and Temuge, and lived a nomadic early life.