The Mongol invasions of Vietnam or Mongol-Vietnamese War refer to the three times that the Mongol Empire and its chief khanate the Yuan dynasty invaded aá????i Viá????t (an old name for Vietnam) during the time of the Trá??§n dynasty, along with Champa: in 1258, 1285, and 1287-88. Although the invasions resulted in disastrous military defeats for the Mongols, both the Trá??§n dynasty and Champa decided to accept the nominal supremacy of the Yuan dynasty in order to avoid further conflicts.