Wat Si Fan, or the Monastery of the Tooth Brushing, was located outside the city island in the northern area of Ayutthaya, in the Hua Ro Sub-district on the west bank of the (new) Lopburi River. It was situated just south of the ruin of Wat Chumphon.

No traces remain of this monastery at ground level.

The site has been completely disturbed by soil replenishment.

Its historical background and period of construction are unknown.

The Royal Chronicles of Ayutthaya mention that an impostor named Tham Thian, formerly an attendant of Prince Aphaithot, the eldest half-brother of King Narai (reign 1656-1688 CE), rebelled again King Phetracha (reign 1688-1703 CE) and gained a significant number of adherents, by giving him out as the prince. The pseudo-prince and his army reached Ayutthaya somewhere in the vicinity of Wat Maha Lok and Wat Monthop. His elephant was struck by one of the eight big guns of the Maha Chai Fortress. He fell off his elephant and was injured. His followers panicked and dispersed in disorder. Tham Thian was captured the following day in the flower garden of Wat Si Fan and executed. His followers became reapers of grass for the elephants.

“In 1060 of the Royal Era, a year of the tiger, the end of the decade, His Highness, the Supreme Holy Lord Child, Prince of the Holy Royal Palace Enclosure of Excellence went to watch boxing with His holy eyes at the elephant corrals. Wretched Tham Thian pretended he was Celestial Lord Aphaithot, who had been taken to be pounded to death at the Monastery of the Carrion, and took the elephant Auspicious Jeweled Seat, which was at Lopburi, to ride on in. The retainers who came along with him numbered about five hundred. Of the farmers harvesting rice [who joined him], some carried spears and some sharpened shoulder poles. Khun and luang of the Prince of the Holy Royal Palace Enclosure of Excellence prostrated themselves to tell the Supreme Holy Lord Omnipotent. The Supreme Holy Lord Omnipotent stated, "If a person possessing merit has really come already, We will hand over [the royal wealth]." His Highness, the Prince of the Holy Royal Palace Enclosure was at the Fort of Grand Victory and Tham Thian halted his elephant at the foot of the embankment. A holy command was issued sending police to scrutinize his person so as to be sure [he was who he pretended to be]. The police came back, prostrated themselves and said, "He’s not Celestial Lord Aphaithot!" Thereupon a holy command was issued to have all eight of the great guns fired forth simultaneously. The followers of Tham Thian accordingly were routed during the evening. Early the next morning they were able to capture the person of Tham Thian in a flower garden of the Monastery of Tooth Brushing and he was taken away and put to death. His entire following was taken to become reapers [of grass for the elephants].” [1]

The inhabitants of many districts near Nakhon Nayok, Lopburi and Saraburi, who had been involved in the rebellion, fled their homes for fear of punishment so that part of the country was almost depopulated. According to Burmese history, these fugitives settled in Burma. [2] Some sources put this event in 1690 CE (Wood), others in 1696 (RCA) or 1698 CE (RCA).

The monastery is shown on the Monthon Krung Kao map of 1916 CE and 1974, 1993 and 2007 CE Fine Arts Department (FAD) maps.

The temple was in geographical coordinates: 14° 22' 27.50" N, 100° 34' 22.83" E.


[1] Cushman, Richard D. & Wyatt, David K. (2006). The Royal Chronicles of Ayutthaya. Bangkok: The Siam Society. pp. 322, 333. [2] Wood, William, A.R. (1924). A History of Siam. Chalermnit Press. p. 219.