The Sukhothai kingdom was a kingdom in the north of Thailand around the city Sukhothai. It existed from 1238 till 1438. The old capital, now 12 km outside of New Sukhothai in Tambon Muang Kao, is now in ruins and is an Historical Park.
The city of Sukhothai was part of the Khmer empire until 1238, when two Thai chieftains, Pho Khun Pha Muang and Pho Khun Bang Klang Hao, seceded and established a Thai kingdom. Pho Khun Bang Klang Hao later became the first king of Sukhothai, Pho Khun Si Indrathit (or Intradit). This event traditionally marks the founding of the modern Thai nation, although other less well-known Thai kingdoms, such as Lanna, Phayao and Chiang Saen, were established around the same time.
Sukhothai expanded by forming alliances with the other Thai kingdoms, adopting Theravada Buddhism as the state religion with the help of Ceylonese monks. Intradit was succeeded by his son Pho Khun Ban Muang, who was followed in 1278 by his brother, Pho Khun Ramkhamhaeng. Under King Ramkhamhaeng the Great, as he became known, who ruled for forty years, Sukhothai enjoyed a golden age of prosperity. Ramkhamhaeng is credited with designing the Thai alphabet (traditionally dated from 1283, on the evidence of the controversial Ramkhamhaeng stele, an inscribed stone bearing the earliest known Thai writing). At its peak, stretching from Martaban (now in Burma) to Louang Phrabang (now in Laos) and down the Malay Peninsula as far south as Nakhon Si Thammarat, the kingdom's sphere of influence was larger than modern Thailand, although the degree of control exercised over outlying areas was variable.
Later kings found their power being gradually eroded by the kingdoms of Lannathai to the north and Ayutthaya to the south. Sukhothai became a tributary state of Ayutthaya between 1365 and 1378, and in 1438 a mere province.
The Kings of Sukhothai
- Pho Khun Si Indrathit (1249- 1257)
- Pho Khun Ban Muang (1257 - 1278)
- Pho Khun Ramkhamhaeng (Ramkhamhaeng the Great) (ruled 1278 - 1298 or 1317)
- Pu Saisongkhram: After Ramkhamheang's death, ruled temporarily in absence of loethai who was on trip to China. He was not styled Pho Khun.
- Pho Khun Loethai (1298 - 1347)
- Pho Khun Nguanamthom (1347)
- Pho Khun Lithai or Thammaracha I (1347 - 1368/1374)
- Thammaracha II or Phya Sai Leu Thai (1368/1374 - 1399)
- Thammaracha III or Phya Sai Luthai (1399 - 1419)
- Thammaracha IV (1419 - 1438)