Đinh Bộ Lĩnh
In the first years of his reign, Đinh Bộ Lĩnh was especially careful to avoid antagonizing Southern Han. In 968, however, he took the provocative step of adopting the title of Emperor (Hoàng Đế) and thereby declaring his independence from Chinese overlordship. He founded the Đinh Dynasty and called his kingdom Đại Cồ Việt. His outlook changed, however, when the powerful Song Dynasty annexed Southern Han in 971. In 972, Đinh Bộ Lĩnh ingratiated himself with the Song by sending a tribute mission to demonstrate his fealty to the Chinese Emperor. Emperor Taizu of Song subsequently recognized the Viet ruler as Giao Chỉ Quận Vương (King of Giao Chi), a title which expressed a theoretical relationship of vassalage in submission to the empire. Well aware of Song's military might, and eager to safeguard the independence of his country, Đinh Bộ Lĩnh obtained a non-aggression agreement in exchange for tributes payable to the Chinese court every three years.