Mongol Empire his generals and other associates, and some Mongols who had previously been allies broke their allegiance. War ensued, and Temujin and the forces still loyal to him prevailed, defeating the remaining rival tribes between 1203 and 1205 and bringing them under his sway. In 1206, Temujin was crowned as the khagan of the "Yekhe Mongol Ulus" (Great Mongol State) at a kurultai (general assembly/council). It was there that he assumed the title of Genghis Khan (universal leader) instead of one of the old tribal titles such as Gur Khan or Tayang Khan, marking the start of the Mongol Empire. Genghis
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