Under King U-Thong. following a series legendomspun-na monarchs expanded Kingdom quickly. Towards the end of the 1300s was driven Khmer away from large areas of central and northern Thailand and Sukhothaifolket finally defeated.
Sa ilalim ng Hari U-sinturon. pagsunod sa isang serye legendomspun-na monarchs mabilis na pinalawak Kingdom. Patungo sa dulo ng 1300s ay hinihimok Khmer ang layo mula sa mga malalaking lugar ng central at hilagang Taylandiya at Sukhothaifolket wakas bagsak.