Somdej Phra Puttajarn Toh Phrom-rangsri or Somdej Toh. He's a son of King Rama II and Nang Ngud of Kamphaengphet Province. He was born before his father became King. Somdej Toh ordained as a novice monk at an age of 13 and become a monk at 21. Well-versed in Buddhist teachings, he was named Maha Toh, the King's monk. In the reign of King Rama IV, he was made Abbot of Wat Rakang-kositaram. He was promoted continuously and finally received the title of Somdej Phra Puttajarn Toh in 1872.
The venurable monk was known to be a good speaker as well as a highly intelligent and compassionate person. He was also persistent and patient. He made many Buddha images for temples and most particularly 73 models of Phra Somdej. He also built many temples. At present PhraSomdej WatRakhang is number 1 and the most famous of all Thailand amulets.