Genghis: Birth of an Empire byConn Iggulden.
This book is about the early life of one of the greatest conquerors in the world history, Gengis Khan. Temujin is born the second son of the Khan of Wolves, a Mongolian tribe living in the plains. During a visit to another tribe, the Khan is ambushed, wounded and died some days later. Temujin's family is then evicted from the tribe and left alone in the plains. However, Temujin survives. He learns to fight against natural and human threats. He unites the Mongolian wanderers under his banner, and step by step, he unites the Mongolian tribes and is becoming one of the strongest Khans of Mongolian plains.
This book is the first one of the new Conqueror series written by Conn Iggulden, who is the author of the Emperor series about Julius Caesar. Wolf of the plains is a really good read.