What is "anouvong"

Chao Anouvong (; ; );, or regnal name Xaiya Setthathirath V (; ; ;), (1767 – 1829), led the Laotian Rebellion (1826 – 1829) as the last monarch of the Lao Kingdom of Vientiane. Anouvong succeeded to the throne in 1805 upon the death his brother, Chao Inthavong (; ), Xaiya Setthathirath IV, who had succeeded their father, Phrachao Siribounyasan (; ) Xaiya Setthathirath III. Anou was known by his father's regal number until recently discovered records disclosed that his father and brother had the same regal name.