I believe this is the sequel to the film Queen Suriyothai. You might want to check that out as well. The movies follow the Thai-Burmese wars of the late 1500's, which is probably why Naresuan is shown wearing European (Portuguese) armor. (Though that bit was a surprise, considering how hot it is in Thailand!)
You can probably find this with subtitles. The Thai movie industry is on a roll these days and are marketing their stuff to geeks like us stateside. Have you seen The Rebel?
Thanks for the tip Dariel, I'll look for it.I couldnt find this movie with english subs, though I did grab a copy of Bang Rajan with subs.Acrobatic flea posted about it a year or so ago and it's been on my "to watch" list for awhile.havent seen the Rebel. is it Thai?