Burmese history started to be recorded in the reign of King Anawrahta (1044-1077). Chinese chronicles mention the Burmese as an ethnic group migrating from southern China about two centuries B.C. After gaining independence from the Nan Chao Kingdom, they migrated southward along the Irrawaddy River. They established a small kingdom in the middle of Burma called Tambadipa in the 10th century. Later on Bagan was established in the mid 13th century during the reign of King Narathihapate (1254-1287). The king was not interested in administration, so the kingdom came under the Mongol rule in 1284. When King Wareru (1287-1301) was enthroned, he put all the Mon cities under his rule. The Mon in the central region of Thailand, generally known as the Davaravadi Kingdom, had its political and administrative center in Nakhon Pathom. It was also the center of Buddhism. Davaravadi architecture and sculpture can be found throughout Thailand and southern Burma. Burmese chronicles mention that the Mon established Satherm as its Buddhist center in the 7th century and spread the religion throughout the region. Sukhothai was in a politically and economically unstable condition due to having no sea routes for trade. King Ramkhamhaeng established the Sukhothai-Motaba trade route with Burma through diplomatic relationships to strengthen its economy and trade. Religion, arts and cultures of Mon, Burma and Sukhothai were derived from India. The three kingdoms had religious, art and cultural relationships with one another.