Ram Khamhaeng
After the death of Ram Khamhaeng, the Sukhothai tributaries broke away. Ram Khamhaeng was succeeded by his son Loe Thai. The vassal kingdoms, first Uttaradit in the north, then soon after the Laotian kingdoms of Luang Prabang and Vientiane (Wiangchan), liberated themselves from their overlord. In 1319, the Hanthawaddy Kingdom to the west broke away. In 1321, Phrae Tak, one of the oldest towns under the control of Sukhothai, became free. To the south, the powerful city of Suphan Buri also broke free early in the reign of Loe Thai.