During this time Thai had strong friendship with neighboring countries. It absorbed elements of various civilizations which they came into contact.
Thai maintained and advanced their culture with China. The potters entered Thai artistry and extensive trade was established with Cambodia and India.
After the death of Khun Pha Muang in 1279, Ramkhamhaeng King, the third son of Si Inthrahit, ascended to the throne. Under the Ramkhamhaeng King, Sukhothai had strong friendship with neighboring China. Ramkhamhaeng King organized a writing system which became the basis for writing and eventually developed to be the modern Thai alphabet.