The decisive character who returned stability to the kingdom and eventually ushered in the Golden Age of Lane Xang was Sourinyavongsa (1637-1694). He aligned Lane Xang through marriage with neighbouring powers, invaded Xiang Khouang, forged a border treaty with Vietnam, and confirmed the watershed line between the Mekong and the Chao Phraya rivers as the frontier with Ayutthaya.

Following Sourinyavongsa's death in 1694, however, the three regions of the country went their separate ways. Sourinyavongsa's grandson Kingkitsalat became the first ruler of an independent Louang Phabang kingdom , while another prince, who called himself Setthathilat II, ruled over Vientiane .

Meanwhile, the kingdom was further divided by the emergence of a new ruling house in the south, at Champasak , under a long lost son of Sourinyavongsa, King Soi Sisamut. Thus the new ruling lines of each of the three major principalities could claim, however tenuously, some link to Fa Ngum and by extension, to Khoun Borom. Rivalry between Louang Phabang and Vientiane was bitter, however, and when a second wave of Burmese invasions swept across the Tai world in the 1760s, forces from Vientiane aligned with the invaders and helped sack Louang Phabang.