Borommarachathirat I

Borommaracha I (Thai: สมเด็จพระบรมราชาธิราชที่ 1, RTGS: Boromma Rachathirat I) or Khun Luang Pa Ngua (Thai: ขุนหลวงพะงั่ว) (1370- 1388) is the third king of Ayutthaya Kingdom. His name Khun Luang Pa Ngua literary means the fifth price.

As the lord of Suphanburi, a powerful rival of Ayutthaya, he forced King Ramesuan from power and took the throne of Ayutthaya. Known as great warrior, his reign marked the expansion of Ayutthaya to the north, subjugating major northern powers such as Sukhothai and Phitsanuloke.

As the king he was famous in warfare. As war was one of the most important duty. He began the successful northward expansion to subjugate old rivals, Sukhothai and Phitsanuloke.

After his death in 1388, his son, Thonglun reigned for only a week. Ramesuan Prince who previously retreated to Lopburi, returned and toppled him. Ramesuan eventually assumed the throne, as the king for the second time.