The War Lord(1976)

Original title: ขุนศึก

Fifteen years after the fall of Ayutthaya, Thai forces led by King Naresuan successfully pushed Burmese troops out of the boundary city of Klaeng. However, this leads to retaliation from the Burmese Kingdom, who sends their troops to crush the remaining influences of Siam. A warlord who had recently lost his teacher may prove to be the only formidable force that Siam has left.