| Viceroy of Siam | |
|---|---|
| กรมพระราชวังบวรสถานมงคล | |
| Style | His Royal Highness |
| Type | |
| Residence | Front Palace |
| Appointer | Monarch |
| Term length | Life tenure or until accession as Sovereign |
| Formation | 1438 |
| First holder | Ramesuan |
| Final holder | Wichaichan |
| Abolished | 28 August 1885 |
| Succession | Crown Prince of Siam |
| Unofficial names | Front Palace lord |
| Deputy | Deputy Viceroy of Siam |
Krom Phra Ratchawang Bowon Sathan Mongkhon กรมพระราชวังบวรสถานมงคล, colloquially known as the Front Palace (Thai: วังหน้า, RTGS: Wang Na), was the title of the uparaja of Siam, variously translated as "viceroy", "vice king" or "Lord/Prince of the Front Palace", as the titleholder resided in the physical residence of the same name. The office of Front Palace was considered second only to the king and regarded as the heir presumptive. The name, with its dual meaning, originated in the Ayutthaya period, and the holder later gained significant powers during the Rattanakosin period. Front Palace occupants were usually a son or brother of the reigning monarch. The office existed until the death of the last occupant, Prince Wichaichan, in 1885. King Chulalongkorn then abolished the office of an heir presumptive, introducing in its stead the Western concept of a crown prince as heir apparent, and styled the new office "Crown Prince of Siam".[1]
- ^ "HM Second King Pinklao". Soravij. Archived from the original on 2013-05-10. Retrieved 2009-10-17.