-style square 'stepped pyramid' chedi,
Wat Chamadevi from the 12th–13th century CE In the twelfth century, during the reign of King Adityaraja, who, together with his brother Chadachota (), were previously princes of
Suphannabhum but fled to Haripuñjaya after the kingdom was annexed by
Lavo of
Tambralinga's prince Kampoch, came into conflict with the Khmers who took over Lavo from
Tambralinga in 1002. Adityaraja, with an assist from
Suphannabhum, Lamphun inscriptions from 1213, 1218, and 1219, mention King Sabbadhisiddhi endowing Buddhist monuments. The early 13th century was a golden time for Haripuñjaya, as the chronicles talk only about religious activities or constructing buildings, not about wars. Nevertheless, Haripuñjaya was besieged in 1292 by the
Tai Yuan king
Mangrai, who incorporated it into his
Lan Na ("One Million Rice Fields") kingdom. The plan set up by Mangrai to overpower Haripuñjaya began by dispatching Ai Fa () on an espionage mission to create chaos in Haripuñjaya. Ai Fa managed to spread discontent among the population, which weakened Haripuñjaya and made it possible for Mangrai to take the kingdom over. Phraya Yi Ba, the last king of Haripuñjaya, was forced to flee south to
Lampang. == List of rulers ==