|Vice King of Siam|
|Tenure||21 July 1824 – 1 May 1832|
|Appointed||Nangklao (Rama III)|
|Born||21 October 1785
Kingdom of Ayutthaya
|Died||1 May 1832 (aged 46)
Bangkok, Kingdom of Siam
|Issue||20 sons and daughters with various consorts|
|Father||King Buddha Yodfa Chulaloke (Rama I)|
|Mother||Princess Nui Yai|
Somdet Phra Bawonratchao Maha Sakdiphonlasep (Thai: สมเด็จพระบวรราชเจ้ามหาศักดิพลเสพ; October 21, 1785 – May 1, 1832) was the Vice King appointed by Nangklao as the titular heir to the throne as he was the uncle to the king.
Prince Arunotai was the son of King Buddha Loetla Nabhalai and his concubine Nuiyai. He was later appointed the Kromma Muen Sakdiphonlasep and became acquitted with his half-nephew Kromma Muen Chetsadabodin during the wars with Burma. Kromma Muen Chetsadabodin was crowned as King Nangklao (Rama III) in 1824 and, consequently, Sakdiphonlasep was made the "Second King". He led the Siamese armies into Isan to fight with King Anouvong of Vientiane in 1826.
Sakdiphonlasep ordered the construction of the Bowonniwet Temple (lit. temple where the Front Palace lived) - the seat of the Sangharaja today and where Prince Mongkut (future Rama IV) became an abbot. In 1829, he ordered the Buddha Chinnasri - a 900-year-old Sukhothai Buddha statue from Pitsanulok - to be floated along the river and placed at the Bowonniwet Temple.
His funeral procession was held 2 April 1833, with cremation set for seven days later. The king, through the Phraklang, invited US diplomat Edmund Roberts and party to witness the procession, which Roberts describes in journal. Roberts notes that one of the sons of the wang-na watches at the temple, near the funeral pile, night and day, till the body is consumed; the ashes of the consumed body are then thrown into the river with many ceremonies; and the unconsumed bones are then delivered to the priests, and made into household gods [sic]. (Roberts refers to Buddhist monks as "Talapoy," from Portuguese talapão from Burmese tala poi our lord.)
- Roberts, Edmund (Digitized October 12, 2007) [First published in 1837]. "Chapter XIX—Procession to the funeral pile of Wang-Na or Second King.". Embassy to the Eastern Courts of Cochin-China, Siam, and Muscat: In the U. S. Sloop-of-war Peacock ... during the years 1832-3-4. Harper & brothers. pp. 289–70. OCLC 12212199. Retrieved 25 April 2012. Check date values in:
Chakri DynastyBorn: 21 October 1785 Died: 1 May 1832