Fa Ngum
The younger brother, Fa Ngum, married one of the king's daughters and in 1349 set out from Angkor at the head of a 10,000 man army. His conquest of the territories to the north of Angkor over the next six years reopened Mongol communications with that place, which had been cut off. Fa Ngum organized the conquered principalities into provinces, and reclaimed Muang Sua from his father and elder brother. Fa Ngum was crowned king of Lan Xang at Vientiane, the site of one of his victories, in June 1354. Lan Xang extended from the border of China to Sambor below the Mekong rapids at Khong Island and from the Vietnamese border to the western escarpment of the Khorat Plateau.