Trần Thái Tông

Trần Thái Tông (Trần Cảnh; 1218–1277) was the founding emperor of the Trần dynasty. In 1226 his uncle Trần Thủ Độ arranged his marriage to the last Lý ruler, Lý Chiêu Hoàng, who abdicated to him.

In 1257 Mongol envoys demanded passage through Đại Việt; after they were imprisoned, Uriyangkhadai invaded. The emperor led his army from an elephant but was defeated. Uriyangkhadai forced the court to abandon Thăng Long and held the capital nine days before withdrawing, after which Thái Tông agreed to tribute.

A learned Buddhist, he authored the Khóa Hư Lục. He abdicated in 1258 for his son Trần Hoảng and died as retired emperor.