Kingdom of Vientiane
Lao settlers began gradually moving across the Mekong into Isan between the 14th and 16th centuries. Major cities were established at Loei, Viang Khuk, Nong Khai, Nong Bua Lamphu (traditionally held by the crown prince), Sakon Nakhon, Nakhon Phanom, Roi Et, Suwannaphume, and Champasak. Additional settlements were located Nong Han Noi, Mahukhanakhon, and a number of settlements across the Mekong from Vientiane including Sri Xiang Mai, Phon Phao, Tha Bo, Say Fong, and Phon Phisai. Many of these early settlements were destroyed or abandoned in the aftermath of the Lao rebellion (1826-1828). Lan Xang was divided by a succession dispute after the death of King Sourigna Vongsa in 1700, into the competing Kingdom of Vientiane, Kingdom of Luang Phrabang and Kingdom of Champasak. Most of what would become the Isan was split between Vientiane and Champasak.