Chao Phraya Phitsanulok (Common name: Ruang) was the origin of Rochanakul Noble Family. He was the highest rank of government official in Ayutthaya realm since 1767, and the Leader who set up as rulers at the 2nd fall of Ayutthaya with King Ekatat as the last ruler. His full title conferred by the King was "Chao Phraya Surasriphismadhiraj Jatibatayadhipesvaradhibodi Abhairiphiriyabhrakrombhahu". His father was the Brahman named “Sirivadhana” who was the royal priest serving for the King Narai or Somdet Phra Ramadhibodi III His father full title conferred by the King was "The Royal Brahman Rajsubhavadisriparamahongsa Vongsapurisotomphromayanvipulasilasucharitta, the Priest vivitdhavedayaphromapuddhacharaya" or Brahman “Sirivadhana”. Chao Phraya Phitsanulok had one elder brother named Chao Phraya Mahasompati.