Back to Royalty Index
The Crown Princes and Maha Uparajas of Siam (Heirs to the Siamese Throne)
Relationship with the King
Ayudhya Era
King Boroma Trilokanaj (1448-1488) Prince Indracha (1448) Eldest son Became King Boromrajadhiraj III (Pra Indracha) 1488-1491
King Boromrajadhiraj III (1488-1491) Prince Chethadhiraj Younger brother Became King Ramathibodi II (Pra Chethadhiraj) 1491-1529
King Ramathibodi II (1491-1529) Prince Atitayawongsa Son As Uparaja, he was Prince of Bisnulok, and governed that town

King Naresuan the Great (Sanpetch II) 1590-1605 Second King E-ka Tosaros (Sanpetch III) Brother Was given the title of Second King and not Heir to the Throne, as he was always in battles along side King Naresuan.
King E-ka Tosaros (Sanpetch III) 1605-1610 Prince Sutasna Son The prince drank poison and died before he became king.
King Songtam (Pra Indra Raja) 1611-1628 Prince Sri Soraraksa Son Was Heir to the Throne for 7 days and died.

King Sri Sutham Raja (Sanpetch VII) 1656 Prince Narai Nephew Was Heir for 2 months. Had arguments with the King, so he took over the throne. Became King Narai the Great (Ramathibodi III) 1656-1688

King Petraja 1689-1703 Kun Luang Sorasak Adopted son Became King Sua (1703-1708)
King Sua 1703-1708 Prince Petch Eldest son Became King Tai Sra (Sanpetch IX) 1708-1732
King Tai Sra (Sanpetch IX) 1708-1732 Prince Por Younger brother Became King Boroma Kos (Boromrajadhiraj V) 1732-1758
King Boroma Kos (Boromrajadhiraj V) 1732-1758 (1) Prince Dharma Dhibes, Kromma Kun Senapitksa Eldest son Was imprisoned.
  (2) Prince Utumporn, Kromma Kun Pornpinij Third son Became King Utumporn (1758). The second son, Prince Ekatas was skipped over as he was deemed not fit to be King by his father. In the same year, Prince Ekatas wished to be king, so his younger brother gave up the crown and went into monkhood. The new king was styled King Suriyasna Amarindra (King Ekatat) 1758-1767
Ratanakosin Era
King Rama I (Phutthayotfa Chulalok) 1782-1809 (1) Krom Pra Rajawang Bavorn Maha Surasinghanath (1782) Brother Died 1803.
  (2) Prince Kromma Luang Issara Sunthorn (1806) Eldest son Became King Rama II (1809-1824)
King Rama II (Phutthaloetla Naphalai ) 1809-1824 Krom Pra Rajawang Bavorn Maha Senanuraksa Brother Died 1818.
King Rama II did not name a successor after the death of his Heir, so there was a consensus that a son, Prince Kromma Muen Jesada Bodin should take the throne, and was styled King Nangklao or Rama III.
King Rama III (Nangklao) 1824-1851 Krom Pra Rajawang Bavorn Maha Sakdi Polsep (1824) Uncle, son of King Rama I Died 1832.
King Rama III did not name a successor after his uncle whom he had name Heir to the Throne died. A consensus was reached and Prince Monkut was invited to take the throne.
King Rama IV (Mongkut) 1851-1868 Second King Pinklao (1851) Brother Second King Pinklao became the second Second King of Siam. He died in 1865.
King Rama V (Chulalongkorn) 1868-1910 (1) Krom Pra Rajawang Bavorn Vichaicharn Cousin, son of Second King Pinklao Died 1885.
The First Heir during the reign of King Rama V was named by a consensus. After his death, the King took the initiative of abolishing the title of Krom Pra Rajawang Bavorn (Front Palace) and officially created a Crown Prince of Siam, choosing his eldest Royal son to take the position.
  (2) Crown Prince Maha Vajirunhis Eldest son The prince became officially the first Crown Prince of Siam. He died in 1895.
  (3) Crown Prince Maha Vajiravudh Second son Became King Rama VI (1910-1925)
King Rama IX (Bhumibol Adulyadej) 1946-2016 Crown Prince Maha Vajiralongkorn Eldest son Crown Prince Maha Vajiralongkornis the Third Official Crown Prince of Siam, and the first of Thailand.
  Related Links  
  Kings of Siam  
  The Crown Prince's Diary, Jan 1886