According to legend, Prince Thanakuman and Queen Hem Chala brought the relic of Buddha to Hat Sai Kaew and built a small pagoda in 291 CE.
When King Si-Thamma Sokarat established the city of Nakhon Si Thammarat, he built a new temple called Wat Phra Borom That on the same site in the Mahayana-style of the ruling Srivijaya Kingdom.
The city of Nakhon Si Thammarat was a prominent city in the ancient kingdom of Tambralinga.
The city was a part of the Srivijaya empire till the early-13th century.

Historians believe that the city was almost emptied by epidemics and war, prompting the king to build a larger stupa in the Sri Lankan-style with public participation and thereby re-develop the town community.
The other religious buildings were constructed between the 13th and 18th centuries including the Wihan-Bodhi Lanka, a roofed cloister around the bodhi tree which is believed to be a sprout of the Mahabodhi tree in the Mahabodhi Temple in Bodh Gaya, India.

The Thai name for the temple, Phra Mahathat Woramahawihan comes from Pali, vara maha dhatu vara maha vihara, literally meaning 'Great Noble Temple of the Great Noble Relics Stupa'.
The stupa, which is bell shaped, is inspired from Sri Lankan Buddhist art reflecting the belief of Ashoka's transmission of the tradition of the stupa from India to Sri Lanka.
The ruler of Nakhon Si Thammarat, who started work on the stupa called himself Sri Dhammasokaraja, which literally means 'Ashoka the great'.
The name of the town Nakhon Si Thammarat, is also derived from Pali, Nagara Sri Dhammaraja, meaning 'town of Dhammaraja'.

The creation of the stupa led to Nakhon Si Thammarat becoming the centre of Thervada Buddhism.
Inscriptions from the Sukhothai Kingdom, speak of the influence the city and the stupa had in spreading and strengthening Thervada Buddhism in the kingdom.
The temple also received patronage from Ayutthaya Kingdom, which ruled over entire present day Thailand between the 14th and 17th centuries.
The stupa and other religious edifices were built over 100 years after construction of the original stupa began.
It underwent massive restoration works in 1612-1616, 1647, 1732-1758, 1769, 1895-1898, 1914, 1972-1974, 1987, 1994-1995 and in 2009.
The temple was nominated to a tentative list of UNESCO World Heritage Sites list in 2012.
According to legend, Prince Thanakuman and Queen Hem Chala brought the relic of Buddha to Hat Sai Kaew and built a small pagoda in 291 CE. When King Si-Thamma Sokarat established the city of Nakhon Si Thammarat, he built a new temple called Wat Phra Borom That on the same site in the Mahayana-style of the ruling Srivijaya Kingdom. The city of Nakhon Si Thammarat was a prominent city in the ancient kingdom of Tambralinga. The city was a part of the Srivijaya empire till the early-13th century. 
Historians believe that the city was almost emptied by epidemics and war, prompting the king to build a larger stupa in the Sri Lankan-style with public participation and thereby re-develop the town community. The other religious buildings were constructed between the 13th and 18th centuries including the Wihan-Bodhi Lanka, a roofed cloister around the bodhi tree which is believed to be a sprout of the Mahabodhi tree in the Mahabodhi Temple in Bodh Gaya, India.
The Thai name for the temple, Phra Mahathat Woramahawihan comes from Pali, vara maha dhatu vara maha vihara, literally meaning 'Great Noble Temple of the Great Noble Relics Stupa'. The stupa, which is bell shaped, is inspired from Sri Lankan Buddhist art reflecting the belief of Ashoka's transmission of the tradition of the stupa from India to Sri Lanka. The ruler of Nakhon Si Thammarat, who started work on the stupa called himself Sri Dhammasokaraja, which literally means 'Ashoka the great'. The name of the town Nakhon Si Thammarat, is also derived from Pali, Nagara Sri Dhammaraja, meaning 'town of Dhammaraja'.
The creation of the stupa led to Nakhon Si Thammarat becoming the centre of Thervada Buddhism. Inscriptions from the Sukhothai Kingdom, speak of the influence the city and the stupa had in spreading and strengthening Thervada Buddhism in the kingdom. The temple also received patronage from Ayutthaya Kingdom, which ruled over entire present day Thailand between the 14th and 17th centuries. The stupa and other religious edifices were built over 100 years after construction of the original stupa began. It underwent massive restoration works in 1612-1616, 1647, 1732-1758, 1769, 1895-1898, 1914, 1972-1974, 1987, 1994-1995 and in 2009. The temple was nominated to a tentative list of UNESCO World Heritage Sites list in 2012.
Wat Phra Mahathat