Phitsanulok, one of Thailand's seventy-six provinces, lies on the upper part of Central Thailand, borders Sukhothai and Uttaradit on the north, Loei and Phetchabun in the east, and Phichit and Kamphaeng Phet to the south. In the northeast boarders Laos.
The name means Vishnu's heaven. The first element Phitsanu (Thai: พิษณุ) is a cognate of Vishnu, a Hindu god (see, e.g. Witsanu, Thai: วิษณุ). Lack of a v sound in the Thai language accounts for the two forms. The second element lok (Thai: โลก) means globe or world.
Unlike the hereditary monarchs of the other royal Malay states, the ruler of Negeri Sembilan is known as Yang di-Pertuan Besar instead of Sultan. The election of the Ruler is also unique. He is selected by the council of Undangs who lead the four biggest districts of Sungai Ujong, Jelebu, Johol, and Rembau, making it one of the more democratic monarchies.
The capital of Phitsanulok is Phitsanulok.
The ethnic composition in 2005 was:Thai, Chinese, Mon and Lao.