The Sukhothai Kingdom (Thai: ราชอาณาจักรสุโขทัย (pronunciation)) was an early kingdom in the area around the city Sukhothai, in north central Thailand. The Kingdom existed from 1238 till 1438. The old capital, now 12 km outside of New Sukhothai in Tambon Mueang Kao, is in ruins and has been designated as a UNESCO World Heritagehistorical park. Modern historians stated that the secession of Sukhothai from the Khmer empire began as early as 1180 during the reign of Po Khun Sri Naw Namthom who was the ruler of Sukhothai and the peripheral city of Sri Satchanalai (now a part of Sukhothai Province as Amphoe). Sukhothai had enjoyed a substantial autonomy until it was re-conquered around 1180 by the Mons of Lavo under Khomsabad Khlonlampong. Traditional Thai historians considered the foundation of the Sukhothai kingdom as the beginning of their nation because little was known about the kingdoms prior to Sukhothai. Modern historical studies demonstrate that Thai history began before Sukhothai. Yet the foundation of Sukhothai is still a celebrated event.