Kublai Khan demands passage through Dai Viet…

Kublai Khan demands passage through Dai Viet for his Yuan army in order to invade of the Kingdom of Champa (in modern central Viet Nam) in 128.

When the Dai Viet Emperor Tran Nhan Tông refuses, the Mongol army, led by Prince Toghan, attacks Dai Viet and captures the imperial capital Thăng Long (modern day Hanoi).

The Viet nobility retreats to the south after burning down the city, depriving the Mongol army of spoils.

Tran Hung Dao and other generals escort the royal family, staying just ahead of the Mongol army in hot pursuit.

When the Mongol army has exhausted their supplies and succumb to tropical diseases, Tran Hung Dao exploits the Mongol's weaknesses and launches counteroffensive strikes.

He manages to draw the Mongol armies into naval battles, leaving the Mongols unable to launch their overpowering cavalry effectively.

The Viet naval force's excellent marine warfare skills are a tactical advantage for the Dai Viet’s military campaign.

The Mongol cavalry commander Sogetu of the southern front is killed in the battle.

In their withdrawal from Dai Viet, the Mongols are also attacked by the Hmong and Yao minorities in the northern regions during their retreat back to Yuan China.