The Mongols were nomadic tribes from the steppes, or grasslands, of central Asia. In AD 1206 they declared Genghis Khan their supreme ruler. He led their conquest of an empire that, by 1279, included all of China and nearly all of Russia, as well as central Asia, Iran, and Iraq.
Mongol military might was based on the speed and ferocity of mounted archers. From galloping horses, Mongol archers let loose arrows that could pierce armor. The riders and the horses were tough, capable of covering more than 100 miles (160 km) a day.
Genghis Khan wanted to live up to his title, which means “prince of all that lies between the oceans.” He aimed to conquer the world and was proud of the fact that, eventually, it took almost a year to ride from one end of his realm to the other.
Genghis Khan began his career as Temujin, the brilliant, ambitious chieftain of one Mongol tribe. He was chosen as supreme ruler, and given the title Genghis Khan, by a gathering of all the Mongol tribes. After his death, in 1227, his empire was divided among his sons.