Liễn was granted the title Nam Việt vương (南越王, "king of Nam Việt") after his father ascended the throne. Liễn was sent to Song China to pay tribute in 973, and was granted the title Grand Preceptor of Inspection (檢校太師 Kiểm hiệu thái sư), Jiedushi of Tĩnh Hải quân (靜海軍節度使 Tĩnh Hải quân tiết độ sứ) and Governor of the Protectorate General to Pacify the South (安南都護 An Nam đô hộ) by Song Taizu. In 975, his title was promoted to "Prince of Giao Chỉ" (交趾郡王, Giao Chỉ quận vương) by Song court. Liễn was regarded as the ruler of Vietnam by Song China, though his father was the de facto ruler.
In 978, Đinh Hạng Lang was consecrated as the crown prince, which made Liễn dissatisfied. Liễn assassinated Hạng Lang in spring 979. In October, Liễn and his father were killed by a eunuch named Đỗ Thích while they were sleeping in the palace courtyard.
- Trần Trọng Kim (2005). Việt Nam sử lược (in Vietnamese). Ho Chi Minh City: Ho Chi Minh City General Publishing House.