In addition to Sukhothai and Ayutthaya, there existed in North Thailand from the end of the 13th to the middle of the 16th century the independent Kingdom of Lan Na. We know nothing of the early history of the country, but it is certain that the Thais had already reigned for some generations in Chiang Saen before they conquered the old Mon Kingdom of Lamphun in 1292. Four years later the new capital of Chiang Mai was founded. The Thai Kings, like their predecessors, were Theravada Buddhists. One king dispossessed the monasteries and reestablished spirit worship and sorcery, but he was dethroned in 1442. His son Tiloka, a pious Buddhist, was an energetic patron of religion and art, and his reign was the golden age of Buddhist art and literature in Chiang Mai.
The Burmese conquered Lan Na in the mid 16th century, and the greater part of the country remained Burmese until the 19th century, when it was finally incorporated in Thailand. The oldest surviving Thai monument in Lan Na is Chedi Si Liem near Chiang Mai, built about 1300. Despite some changes it still bears the mark of the Mon style (Wat Kukut). But the masterpiece of Tiloka’s reign is Wat Chet Yot near Chiang Mai; building was begun in 1455, doubtless because the King wanted to gain special merit by completing it in the Buddhist year 2000 (1457). The monastery is a copy of the Maha Bodhi temple at Bodh Gaya, hut the elegant plaster decorations are completely Thai in spirit, with some features showing Sukhothai influence.
In the sculpture of North Thailand an early and a late style can be distinguished. The Buddha images of the older type have the same characteristics as Indian figures of’ the Gupta period: crossed legs, a round face, large curls, strong lips. The tip of the robe hanging over the left shoulder does not reach the nipple, and the flame on the tip of the ushnisha (the protuberance on top of the head) has the form of a lotus bud. The later type is slenderer, the face oval and the end of the robe longer. The legs are not crossed, but one over the other. The halo is like a long-tongued flame. The most famous specimen of this group is the Buddha Sihing in Wat Phra Singh in Chiang Mai (the name is derived from the designation of the Buddha as Sakyasinha. the “Lion of the Sakya Clan”). The later style greatly resembles that of Sukhothai. Tiloka had conquered the city of Nan in 1449 and transferred artists from there to his capital, and ten years later he took Sawankhalok, which was firmly rooted in the Sukhothai tradition: again he brought artists from there to Chiang Mai. In Lan Na bronze was the favourite material: only in Phayao were some stone-carvings of importance produced.