Ngô Quyền
Ngô Quyền, the first ruler of Đại Việt as an independent state, used the title "Vương" (王, "King"). However, after the death of Ngô Quyền, the country immersed in a civil war known as Anarchy of the 12 Warlords that lasted for over 20 years. In the end, Đinh Bộ Lĩnh unified the country after defeating all the warlords and became the first ruler of Đại Việt to use the title "Hoàng Đế" (皇帝, "Emperor") in 968. Succeeding rulers in Vietnam then continued to use this Emperor title until 1806 when this title was stopped being used for a century.