Wat Phra Si Mahathat was built when Field Marshal Plaek Pibulsongkram was Prime Minister. The Cabinet had agreed to build and name it as Democracy Temple. During the construction, Rear Admiral Thawal Thamrong Navaswadhi went to India to ask for the Lord Buddha’s relics, five branches of the Bhodi and some soil from the place where the Lord Buddha attained his enlightenment to keep in this temple. Hence, the temple was later named as Wat Phra Si Mahathat.