While one of the Thai tribes of the Chao Phraya River was founding Sukhothai kingdom, another tribe in the north-western tableland, called Lanna, was also successful in driving out the Mons influence from the River Ping. In the nineteenth Buddhist century King Meng-Rai of the ancient Chiang-San dynasty was known to have defeated King Ye-Ma, the Mon king of the town of Lamphun, and later built his capital at Chiang Mai.During this time Theravada Buddhism of Ceylon had been brought from their flourishing states in the Mons country and in Sukhothai to the north-western tableland, but was not able to take its firm roots there. In the twentieth Buddhist century through the royal order of King-Kue-Na, several “Lankavangsa” bhikkhus both from Moulmein (Mau-Ta-Ma) and from Sukhothai were invited to Chiang-Mai (750 km. north of Bangkok) to preach their doctrine. Of these bhikkhus along with their followers, one named Ananda was from the town of Mua-Ta-Ma in the Mons country and the other called Sumana was from Sukhothai.

In the following century (B.E. 2020 or 1477 AD) under the auspices of King Tilokara, the thirteenth of Chieng Mai dynasty and under the leadership of Khammadinna Thera, a general Council of bhikkhus which lasted one year was convened at the Maha Bodhivong Vihara. Practically this was the first Council held in Thailand and reflected the intensive study of Buddhism during the time. A collection of Pali texts, compiled by the Thera (Elders) of that glorious age, are now a pride of the those who wished to further their research of Buddhism in the Pali language. Some such texts were Abhidhammayojana, Mulakaccayanayojana. Vinayayojana, Vessantaradipani and Mangalathadipani. In the following (twenty-second) century the town was taken by the Burmese and from time Chiang-Mai became a unhappy town alternately torn by two superior powers i.e. Burma on her north and the kingdom of Ayutthaya on her south.