The Sukhothai Kingdom was an early Thai kingdom that flourished from the 13th to the 15th centuries in what is now northern Thailand. It is often considered the first capital of Thailand and played a crucial role in the development of Thai culture, language, and art. The kingdom is known for its impressive architecture, including the famous Sukhothai Historical Park, which features well-preserved ruins of temples and monuments. The kingdom was founded by King Ramkhamhaeng, who is credited with creating the Thai script and promoting Buddhism as a central aspect of society. The Sukhothai Kingdom eventually declined due to internal conflicts and external pressures, leading to the rise of the Ayutthaya Kingdom in the 14th century.