Taking advantage of Siam’s political chaos, Burmese armies again invaded Siam, and Ayutthaya was forced to prepare for war. Various nobles and imperial subjects visited the former King at the Monastery of the Pradu Tree to persuade him to leave monkhood to prepare the city’s defence. Fearing that the city would be lost to the enemy and having compassion for the city’s residents, Uthumphon gave up his ascetic life at this monastery. King Uthumphon, who believed that his resumption of the crown was to be permanent, soon found his brother intriguing against him, and in 1762 CE, fearing that his life was in danger, he retired once more to his monastery.
"At that time the various nobles and imperial subjects, persuading each other to go to prostrate themselves and beseech the Holy Lord Omnipotent of the Monastery of the Pradu Tree, invited His Majesty to take leave of the monkhood and come out to help with the royal affairs of the realm. The Holy Lord Omnipotent, having compassion in His holy heart for the celestial retainers and commoners and fearing the Holy Metropolis would be lost to the enemy, thereupon took leave of the monkhood and came out to help the Holy Older Brother of the King with royal affairs to defend the realm and protect the Holy Metropolis. He thereupon issued a warrant, being pleased to have Caophraya Aphai Racha, Phraya Yommarat and the Phraya of Phetburireleased from punishment and to have them retain their positions of standing and dignity and administer royal affairs as before. Then He had the retainers and troops of the municipality, as well as the families and food supplies, rounded and driven into the Holy Metropolis. Now the walls of the municipality along the front of the Holy Royal Palace Enclosure on the side toward the edge of the river originally consisted of only a single tier. He had one more tier of walls newly constructed outside and lower than the original walls. And He had teak logs brought up, tied to hang from the boundary stones and pounded into the ground to form barriers to seal off all the water and land gates. Then He had the wheeled guns and tripod guns brought up and positioned at intervals in a line upon the fortifications, and conscripted troops of soldiers to fill the posts and defend the positions around the Holy Metropolis. Then He had the brigades of an army conscripted and was pleased to have Caophraya Maha Sena, as the general of the army, with Phraya Rattanathibet, Phraya Yommarat, Phraya Ratcha Wangsan and all the servants in royal service, lead the brigades of a large army of over two thousand troops out to encamp and engage the armies of the Burmese enemy. They went and established a large number of stockades in a line with each other along the Waterway of the First King." [4]
"One day later on, during the middle of the night, the King issued a holy royal proclamation to have the Holy Younger Brother of the King summoned in for an audience in a place in the Interior [of the Palace Enclosure]. When His Majesty went in He gazed with His holy eyes and saw His Holy Lord and Older sibling unsheathe a holy sword weapon and lay it across His holy lap. He accordingly understood in His holy heart that the King was displeased, would do Him harm, and would not let Him remain among the laity. His Majesty thereupon came back out to His place to the Front [of the Palace Enclosure]. When the waxing half of the eighth month arrived, His Majesty thereupon boarded a holy throne barge and went out to the Monastery of the Fig of the Pure Gold Spray. After entering the holy monkhood, His Majesty came back in to live at the Monastery of the Pradu Tree just as before." [5]
As Burmese troops moved closer to the capital city, all the holy clerics of the Royal Synod were invited to live at monasteries within the city walls. Uthumphon departed from the Monastery of the Pradu Tree to live at the Wat Ratcha Praditsathan. While here, nobles and citizens tried to persuade him to leave monkhood again to protect the city. They wrote pleading messages, wrapped them up, and placed them in his alms bowls. Despite receiving many messages daily, the former King remained a monk. Burmese armies eventually conquered Ayutthaya on 7 April 1767 CE and destroyed the city. King Suriyamarin died in the process. The Burmese defrocked Uthumphon, and he became a common layman. He was then led over the hills to Burma, where he ended his days recounting the past glories of the Kings of Ayutthaya.
"Meanwhile, within the Celestial Capital and Grand Metropolis at that time when the brigades of the Burmese armies had advanced and almost reached the Capital, the Supreme Holy Buddhist Lord Omnipotent commanded [officials] be sent forth to invite all those holy clerics of the Royal Synod who were living in monasteries outside the municipality to come in to live inside the monasteries of the Holy Metropolis. And His Majesty the Supreme Holy Younger Brother of the King, who was in the monkhood at the Monastery of the Pradu Tree, accordingly came in to live at the Monastery of the Royal Foundation. Nobles and citizens persuaded each other to go to speak to and invite His Majesty to leave the monkhood, help with the royal affairs of the realm, and protect and defend the Holy Metropolis just like [He had done] during the campaign of Mang Lòng on the previous occasion, but He did not leave the monkhood at all. Now when His Majesty went to receive food in His alms bowl, the inhabitants of the municipality persuaded each other to write messages, wrap them up and place them in His alms bowl—their gist was to beseech Him to leave the monkhood—and He received packages of messages in His alms bowl in great numbers each and every day." [6]
"The Holy Lord Mang Ra thereupon bestowed bounties, appointed Nemiao to be Yotthaya Wun and placed him in charge of all the groups of Thai. Now as for the Crown Noble of the Monastery of the Pradu Tree—the Holy Lord of Ava had Him defrocked and become a layman. As for all those descendants of the Holy Lineage of the Ruler of the Thai Municipalities—they were sent to establish houses and homes at the Municipality of Cakkai on the banks of the far side of the Mother of Waters, directly across from the Municipality of Ava.” (5) [7]