With the rise of King Taksin, his Thonburi Kingdom began expanding direct control over the region. Thonburi forces invaded and took control of the Kingdom of Luang Phrabang and the Kingdom of Vientiane and Isan entered its direct orbit.

In 1718, Lao settlers in the company of an official in the service of King Nokasad of the Kingdom of Champasak founded mueang Suwannaphum.[7]

During late 18th century, the Lao kingdoms of Luang Phrabang and Champasak were increasingly at odds with Vientiane. As Vientiane struggled to maintain control of Isan, a number of dissidents began migrating from Vientiane and taking refuge in Isan. Most of them recognized Siam as their suzerain according to the mandala system. Under this system, mueang leaders were granted something equivalent to a fiefdom and Thai feudal titles as governor, having full right of rulership over their towns. Thus they eventually became the subjects of the royal court in Bangkok. New towns were founded such and Chaiyaphum along with many minor towns such as Han Chai Cham Na.