Although it is not at all that clear. The Royal Chronicles of Ayutthaya mention that King
Boromracha II, after invading Cambodia in 1431, removed a large number of sacred
images of oxen, lions and other animal creatures from Angkor and on return to
Ayutthaya presented all the images as offerings, some at Wat Maha That and some at
the Phra Sri Sanphet Monastery. [1] This indicates that at the fall of Angkor, Wat Phra
Sri Sanphet was already in existence and occupied a prominent place.
King Ramathibodi II’s first act after his throne ascendance in 1491 was to cremate the
remains of his father King Borom Trailokanat (r. 1448-1488) and his elder brother King
King Boromracha III (r. 1488-1491). In 1492 King Ramathibodi II built two chedi: the
chedi to the east was to store the ashes of his father; the chedi to the west (the actual
middle one) was for his older brother.
“In 861, a year of the goat, the holy Preaching hall of the Phra Si Sanphet
Monastery was founded.”
In 1499 a hall of worship called “Vihara Luang” (Royal Chapel) was built on the
grounds. The next year King Ramathibodi II gave orders for a gigantic image, of Buddha
to be cast, and installed in Wat Sri Sanphet. This image, representing Buddha in a
standing posture, was 16 meter high, and the pedestal was 8 meter in length. The statue
was named after the temple. The head was 2 m long and 1.5 m wide, while its chest was
5.5 m wide. The bronze core weighted close to 64 ton while its surface was covered
with 343 Kg of gold and took more than three years to complete. It was said that it was
the largest and nicest standing image of Buddha recorded as having ever existed in the
world. This statue, called “Phra Sri Sanphetdayan”, became the main object of
veneration in the royal chapel.