Photo of the Fire King from http://www.mhro.org/cultural-preservation
Sir James Frazer in his monumental, unreadable ethnological masterpiece The Golden Bough (about a dozen volumes – no, I haven’t read it, just this page), tells how the King of Cambodia used to send gifts and letters every year to the Kings of Water and Fire. (That’s the King of Fire up above, though he died in the 80s)
The King of Water had a sacred flower and fruit, with which he could cause a great flood to sweep over the world should he choose, while the King of Fire had a sacred sword which would cause the world to end if he drew it from its sheath.
According to Frazer they lived in the backwoods in seven towers on seven mountains, moving to a new tower each year. When the seven years were up they’d be put to death. The moment the cremation fire was lit all possible successors – the title was hereditary – would run off to the forest to hide, and the first to be found would become the new king.
Possibly (probably) more reliable than Frazer is Joachim Schliesinger, the author of a series of solid-looking books on Southeast Asian tribes. Unfortunately I can’t find out anything about him, but one of the books is called White Elephants in Thailand and Neighboring Countries. That’s one I’d like to get. Anyway, in his Ethnic Groups of Cambodia Volume 3 he talks a little about the two kings. They do not live in seven towers on seven hills, and they are not executed every seven years, but the King of Fire did (or does) possess a sacred sword which fell from heaven long ago and is now kept hidden.
Also very useful is Oscar Salemink’s The Ethnography of Vietnam’s Central Highlanders (2003). He says that the Vietnamese government doesn’t like the “backward” culture of the Jarai and are trying to stamp it out. The old kings of Water, Air and Fire have all died in recent decades and the authorities aren’t allowing new ones to be installed. Jarai cadres in the Party are pleading with their superiors for the installation ceremonies to be permitted, but although the Vietnamese Constitution guarantees freedom of religion, the Kings are classified as superstition, which is forbidden. But things aren’t all black and white, and Salemink’s chapter is fascinating.
Meanwhile, if you visit Siem Reap, you can see a totally vulgarised version put on for tourists at something called the Cambodian Culture Village – but the blurb says, quite accurately, that there seems to be some connection between this Jarai sacred sword and the sword that’s part of the Khmer royal regalia. (The website calls the tribe Phnorng, but they mean Jarai).