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Wat Yai Chai Mongkhon: Phraya Tak's flotilla base in the war of the fall
Wat Yai Chai Mongkhon is a large temple south-east of Ayutthaya's city island. Most people know it for the Chai Mongkhon chedi, tied to the story of King Naresuan. But in the war of the second fall, this temple was where Phraya Tak and Phraya Phetchaburi stationed their flotilla during the floods at the end of 1766, and the point from which the two went out to fight at Wat Sangkhawat, the battle that changed Phraya Tak's thinking about the defence of the city.
This place through the periods
A large temple south-east of the city, founded in 1357 as Wat Pa Kaeo. Its great Chai Mongkhon chedi is tied to stories of King Naresuan's time. In the years when the young Sin was growing up, it was an important temple, visible from the Pa Sak River.
During the floods of November 1766, Phraya Phetchaburi (Rueang) and Phraya Tak brought a flotilla and stationed it at Wat Yai Chai Mongkhon, to meet the Burmese, who were moving by boat across the flooded fields east and south of the city. From here the two went out to fight at Wat Sangkhawat.
After the fall the temple was deserted, like the other temples outside the city island. The great chedi still stood, but there were no monks to look after it.
Through the Thonburi years and several reigns after, the temple remained deserted, until monks came back to spend the rains retreat here in 1957.
One of the temples in Ayutthaya where most people come to pay respect to the Buddha. The main chedi towers over it, rows of Buddha images line the gallery, and there is a reclining Buddha in the open air.
Wat Pa Kaeo and the Chai Mongkhon chedi
The chronicles record that King Ramathibodi I had this temple built in 1357 for monks of the Pa Kaeo order. The temple later became tied to the story that King Naresuan had a great chedi built to commemorate his victory in the elephant duel, hence the name Chai Mongkhon ("auspicious victory") chedi. The temple stands across the Pa Sak River from the city island, and in the flood season the fields around it turn into a wide sheet of water.
This terrain made Wat Yai Chai Mongkhon a strategic point in the flood season: whoever controlled the boats could move forces to the east and south of the city.
Phraya Tak's flotilla, late 1766
The Ayutthaya court hoped the floods would force the Burmese to withdraw as in earlier wars, but the Burmese commanders had prepared boats and set up camps on the high ground around the city. In November 1766, when the water was at its highest, Phraya Phetchaburi (Rueang) and Phraya Tak brought their flotilla and stationed it at Wat Yai Chai Mongkhon, to meet the Burmese flotilla in the fields to the south-east.
From here the two took their boats to fight the Burmese in the fields near Wat Sangkhawat. Phraya Phetchaburi's flotilla was surrounded and broken, and he was killed. The chronicles say the forces of Phraya Tak and Luang Son Seni did not go to his aid. After this fight Phraya Tak moved his camp to Wat Phichai, and began to think about going out to find forces outside the city.
From deserted temple to one of the most visited
After the fall Wat Yai Chai Mongkhon lay deserted for a long time, until monks came back to spend the rains retreat here in 1957. Today it is one of the temples in Ayutthaya where most people come to pray. You can climb the stairs of the main chedi; rows of Buddha images line the gallery, and there is a large reclining Buddha in the open air.
To follow Phraya Tak, see this temple together with Wat Phichai Songkhram, about a kilometre and a half to the north. These two temples were Phraya Tak's bases in the last phase of the war, before he broke out through the siege.
That river battle in the chronicles
The Royal Autograph version of the chronicle says the court sent Phraya Tak, Phraya Phetchaburi and Luang Son Seni out to take up position at Wat Pa Kaeo to intercept the Burmese boats. Phraya Phetchaburi led 5 boats into the attack but was surrounded. The Ayutthaya side lost seventy-odd dead and the Burmese 41, and Phraya Phetchaburi was captured and died. Phraya Tak and Luang Son Seni kept their boats moored and did not go to his aid, then withdrew to Wat Phichai.
Historians read this passage differently. Some see it as the point at which Phraya Tak began to think of breaking away; others point out that the chronicles, revised at a later date, may tell it this way in order to explain his leaving the capital a few weeks later. You can compare the evidence on the chronicles page about Phraya Tak leaving Ayutthaya.
Where historians still disagree
- Why Phraya Tak did not help Phraya Phetchaburi: the chronicles give no clear reason. Some explanations say Phraya Tak's force was too far away or saw that it could not win; others tie it to conflicts at court for which Phraya Tak had already been reprimanded.
Visiting information
- Opening hours: Daily, approximately 8:00 am–5:00 pm (as of 2026)
- Admission: Free for Thai visitors; foreign visitors pay a maintenance fee (THB 20 as of 2026)
- This is a working temple with resident monks, so dress modestly and cover your shoulders and knees.
- Mornings are cooler and less crowded than late morning.
- You can go on to Wat Phichai Songkhram, about 1.5 km to the north.
Opening hours and admission fees may change, so please check before you go.
Frequently asked questions
What does Wat Yai Chai Mongkhon have to do with King Taksin?
In November 1766, during the Burmese siege, Phraya Tak and Phraya Phetchaburi stationed their flotilla at this temple before going to fight at Wat Sangkhawat.
What are Wat Yai Chai Mongkhon's opening hours?
Daily, about 8:00 am–5:00 pm, as of 2026. Check before you go.
Last updated 13 November 2026