Mongol invasions of Vietnam

Four major military campaigns were launched by the Mongol Empire, and later the Yuan dynasty, against the kingdom of Đại Việt (modern-day northern Vietnam) ruled by the Trần dynasty and the kingdom of Champa (modern-day central Vietnam) in 1258, 1282–1284, 1285, and 1287–1288. The campaigns are treated by a number of scholars as a success due to the establishment of tributary relations with Đại Việt despite the Mongols suffering major military defeats.

Source: Wikipedia — Mongol invasions of Vietnam (CC BY-SA 4.0)