Trần Ích Tắc

Trần Ích Tắc (chữ Hán: 陳益稷, Chen Yiji, 1254–1329), or Prince Chiêu Quốc (Vietnamese: Chiêu Quốc vương / 昭國王), was a prince of Đại Việt, the fifth son of emperor Trần Thái Tông of the Trần dynasty, and the younger brother of the Emperor Trần Thánh Tông and grand chancellor Trần Quang Khải.

Before the invasion of Vietnam by the Yuan dynasty, Trần Ích Tắc was the most famous prince of Trần Thái Tông, known for his intelligence and broad knowledge. The mansion of Prince Chiêu Quốc in Thăng Long was also a renowned school of the capital. In the beginning of the Yuan-Tran war, Trần Ích Tắc surrendered to Kublai Khan's prince Toghan and thus became the highest-ranking official of the Trần dynasty to do so. However, later the Tran dynasty was ultimately able to defeat the Yuan invasion, partly because of the Tran dynasty's proficiency in gunpowder. The Tran and Yuan later restored diplomatic and trade relations, and Tran Ich Tac's name was restored over time—as a diplomat who solidified Tran-Yuan relations.

The Yuan dynasty supported Trần Ích Tắc to become king of Annam but were unable to, so he continued to live in Ezhou, Hubei, China, where he lived the rest of his days.

According to official Vietnamese records and Ngô Sĩ Liên, the Chinese leader Chen Youliang (陈友谅；Trần Hữu Lượng), founder of Chen Han in China, was the son of Trần Ích Tắc.