Organization of the Mongol Empire under Genghis Khan it also strengthened Mongol society as a whole. Genghis Khan’s united Mongol nation formed the foundation of the largest continuous land empire ever known. A wise statesman, Genghis also established Mongolian-style democracy that respected the ethnic and cultural diversity of his Empire. His government left many long-lasting legacies: Genghis Khan preferred to rule through existing hierarchies, but where he was resisted he destroyed the existing aristocracy. Nevertheless, he created at the same time a rough meritocracy among the Mongols. Positions of honor were given on the basis of bravery in battle or outstanding loyalty, as opposed to the old system
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