Fa Ngum
In the 1300's, the Lao prince Fa Ngum was exiled to lived in the royal court of Angkor. His father-in-law, the King of Cambodia, gave him a Khmer army to create a buffer state in what is now Laos. Fa Ngum conqured local principalities and established the Kingdom of Lan Xang. With the assistance of Khmer scholars, Fa Ngum introduced Theravada Buddhism and the culture of the Khmer Empire to the region.