Karkashin mulkin Sarki Sourigna Vongsa (1637–1694) Lan Xang ya sami zaman lafiya da sabuntawa na tsawon shekaru hamsin da bakwai.^[45] A lokacin Lan Xang sangha ya kasance a koli na iko, yana zana sufaye da nuns don nazarin addini daga ko'ina cikin kudu maso gabashin Asiya.Adabi, fasaha, kiɗa, raye-rayen kotu sun sami farfaɗowa.Sarki Sourigna Vongsa ya sake duba yawancin dokokin Lan Xang kuma ya kafa kotunan shari'a.Ya kuma kulla yarjejeniyoyin da suka kulla yarjejeniyar kasuwanci da iyakoki tsakanin masarautun da ke kewaye.^[46]A cikin 1641, Gerritt van Wuysthoff tare da Kamfanin Yaren mutanen Gabashin Indiya sun yi hulɗar kasuwanci ta yau da kullun tare da Lan Xang.Van Wuysthoff ya bar cikakken asusun Turai na kayan ciniki, kuma ya kafa dangantakar kamfani tare da Lan Xang ta Longvek da Mekong.^[46]Lokacin da Sourigna Vongsa ya mutu a shekara ta 1694, ya bar jikoki guda biyu (Prince Kingkitsarat da Prince Inthasom) da 'ya'ya mata biyu (Princess Kumar da Princess Sumangala) tare da ikirarin sarauta.An samu sabani na gadon sarauta inda dan uwan ​​sarki Yarima Sai Ong Hue ya fito;Jikokin Sourigna Vongsa sun gudu zuwa gudun hijira a Sipsong Panna da Gimbiya Sumangala zuwa Champasak.A cikin 1705, Yarima Kingkitsarat ya ɗauki ƙaramin ƙarfi daga kawunsa a Sipsong Panna ya nufi Luang Prabang.Dan uwan ​​Sai Ong Hue, gwamnan Luang Prabang, ya gudu kuma aka nada Kingkitsarat sarauta a matsayin sarki mai hamayya a Luang Prabang.A cikin 1707 an raba Lan Xang kuma an sami mulkokin Luang Prabang da Vientiane.