This is interesting: Mangrai was NOT the only one to successfully resist the Mongols!
http://en.wikipedia.org/wiki/Tr%E1%BA%A7n_H%C6%B0ng_%C4%90%E1%BA%A1o
Author of many self-published books, including several about Thailand and Chiang Rai, Joel Barlow lived in Bangkok 1964-65, attending 6th grade with the International School of Bangkok's only Thai teacher. He first visited ChiangRai in 1988, and moved there in 1998.