The Sukhothai Kingdom (Thai: สุโขทัย, RTGS: Sukhothai, IAST: Sukhodaya, pronounced [sù.kʰǒː.tʰāj]) was a post-classical Thai kingdom (mandala) in Mainland Southeast Asia surrounding the ancient capital city of Sukhothai in present-day north-central Thailand. The kingdom was founded by Si Inthrathit in 1238 and existed as an independent polity until 1438, when it fell under the influence of the neighboring Ayutthaya after the death of Borommapan (Maha Thammaracha IV).