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,
Mongol invasions of Vietnam repeatedly ignored demands to attend the Yuan court and offer his personal submission to the Great Khan. By 1266, a standoff developed, as the Emperor Thánh Tông sought a loose tributary relationship, while Kublai demanded full submission. Trần Thánh Tông sent an official letter requiring Kublai to take his darughachi back. Because of civil war in the Mongol Empire, and the Yuan conquest of Song China, armed conflict was delayed. Instead, Kublai reminded him of the peace treaty signed by the Mongols and Đại Việt. As a result of the Mongol conquest of the Song Empire, by 1278–79, Mongol troops