Leader of the Lao People's Revolutionary Party who held office as the first President of Laos from 1975 to 1991.
He joined the Indochinese Communist Movement while studying in Vietnam.
As one of the Three Princes, he fought to end France's occupation in Laos.
He was married to Viengkham Souphanouvong at the time of his death.
He was the brother of Prince Boun Oum .