Background
He was born in 1218 during the last years of the Lý Dynasty.
He was born in 1218 during the last years of the Lý Dynasty.
Trần Thái Tông"s given name was "Trần Cảnh" (陳煚). His progress to the throne in particular and the replacement of the Trần Dynasty over the Lý Dynasty in general were mostly thanks to the efforts of Trần Thủ Độ, Trần Cảnh"s uncle. At that time, Trần Thủ Độ was the front commander of citadels of the Lý Dynasty.
Trần Cảnh"s father, Trần Thừa, was also an official under the Lý Dynasty, like Trần Thủ Độ.
He had been "Nội thị khán thủ", one of the most important officials in the Lý Dynasty. During his reign Trần Thái Tông used three era names: Kiến Trung (1225–1232), Thiên Ứng Chính Bình (1232–1250) and Nguyên Phong (1251–1258).
He commanded the armies, and decided not to protect his capital from the first Mongol invasion of Vietnam in 1258. Instead, with the help of his military commanders, he opted for small scale battles and guerrilla warfare.
Even though he finally forced the Mongols to retreat, he agreed to send tribute every 3 years to the court of the Mongol Empire.
A prodigious writer, he left behind a substantial number of works, of which only a small number survive. Trần Liễu was Trần Thái Tông"s elder brother. In 1237, Trần Thái Tông and Empress Chiêu Thành still did not have any son to maintain the continuation of his dynasty, due to Trần Trịnh"s premature death.
At that time, Princess Thuận Thiên, Trần Liễu"s wife, had been pregnant with Quốc Khang for 3 months.
Taking that advice, the emperor gave injunction to create princess Thuận Thiên empress Thuận Thiên, and demote Chiêu Hoàng down to princess. Because of this, Trần Liễu took his army to Cai River to rebel.
This incident embarrassed Trần Thái Tông and he left the capital for Yên Tử mountain. Two weeks later, Trần Liễu surrendered.
Trần Thủ Độ intended to behead him, but Trần Thái Tông covered him by his body, so that Trần Thủ Độ could not do anything.
After that, he gave him his territory, consisting of Yên Phụ, Yên Dưỡng, Yên Sinh, Yên Hưng, Yên Bang. Due to the name of his territory, Liễu is also called Yên Sinh Vương.