Fa Ngum
The Lao kingdom of Lan Xang was established in Luang Prabang in the 14th century by Fa Ngum. The kingdom's name means "Million Elephants", echoing the name of the neighboring northern kingdom of Lan Na "Million Rice Paddies". As the Khmer Empire continued to retreat under pressure from the neighboring Tai kingdoms of the Ayutthaya Kingdom and Lan Xang. Ayutthaya established a presence at Nakhon Ratchasima and Phimai. However, the bulk of the Khorat Plateau fell into the mandala of Lan Xang.