Mongol Empire a son of a Mongol chieftain. As a young man he rose very rapidly by working with Toghrul Khan of the Kerait. The most powerful Mongol leader at the time was Kurtait; he was given the Chinese title "Wang", which means Prince. Temujin went to war with Wang Khan. After Temujin defeated Wang Khan he gave himself the name Genghis Khan. He then enlarged his Mongol state under himself and his kin. The term Mongol came to be used to refer to all Mongolic speaking tribes under the control of Genghis Khan. His most powerful allies were his father's friend,
Society of the Mongol Empire when the Song dynasty started replacing their copper coinage with paper currency. When the Mongols invaded Song China they started issuing their own Mongolian bills in 1227. This first attempt by the Mongols did not last long because the notes issued expired after several years and were inconsistent throughout the parts of the Mongol Empire that issued them. In 1260, Kublai Khan created the Yuan Mongol's first unified paper currency with notes that did not have any expiration date. To validate the currency, it was made fully exchangeable to silver and gold and was accepted as tax payments. Currency distribution