Kingdom of Vientiane
In Isan, Vientiane Lao is the primary form of Isan spoken in the northern third of the region which was long settled since the days of Lan Xang and was ruled as part of the Kingdom of Vientiane, including most of Nong Khai, Nong Bua Lamphu, eastern Loei and portions of Saiyaphum and Bueng Kan. As a result of the Lao rebellion of 1826 the "Tai Wiang" (, ), ), 'Vientiane people' of the city and surrounding parts of the kingdom, were rounded up by Siamese armies and forced to the right bank, greatly boosting the Lao population of what is now Isan. The Tai Wiang strengthened numbers in the northern third, where Vientiane Lao was traditionally spoken, but were scattered across the Isan region overall, with heavier concentrations in Yasothon, Khon Kaen and Hoi Et provinces. This likely had a leveling effect on the Lao language as spoken in Isan, as most Isan speakers regardless of speech variety are prone to using /ʋ/ as opposed to /w/ and the informal conversion of syllable-initial /k/ to /tɕ/ in relaxed, informal speech, which in Laos, is particularly characteristic of Vientiane speech. For example, the word "kaem" (, "kèm", ), 'cheek', is often pronounced *"chaem" (*, * "chèm", *).