Archomental
Archomentals are a storied race of beings from Dungeons & Dragons. They are essentially the "exemplars" (gods/leaders) of the Elementals.
1st Edition
Gary Gygax created the first archomentals - or, as he called them, "Princes of Elemental Evil" - in this edition. They basically served the same purpose as demon lords and arch devils, but for the elemental planes of Earth (Ogremoch), Fire (Imix), Air (Yan-C-Bin) and Water (Olhydra).
2nd Edition
Planescape brought the archomentals back and gave them counterparts (since this was the Grid-Filling Edition), the Princes of Elemental Good; Sunnis of Earth, Chan of Air, Ben-Hadar of Water and Zaaman Rul of Fire.
3rd Edition
The Archomentals were given their official name of "Archomental" in Dragon Magazine for this era, with the Archomentals of Evil appearing in Dragon #347 and their Good counterparts appearing in Dragon #353. This edition also introduced the concept of Archomentals of the Paraelemental planes, though only five are mentioned (Bwimb of Ooze, Ehkahk of Smoke, Chilimba of Magma and Cryonax of Ice) and only Cryonax got stats.
4th Edition
In 4e, archomentals, renamed "Primordials", got a HUGE promotion. With Points of Light mythos styled after ancient Greco-Roman myths, the multiverse was now created originally by the Primordials/Archomentals, with the Gods coming along later and adding permanency and mortal life to everything. This ticked off the Primordials, and so they fought the Dawn War. The gods killed and imprisoned a huge bunch of Primordials, and others were corrupted into the first Demon Lords, and so the Dawn War came to an end.
Because 4e went for the Elemental Chaos rather than the rigid grid-system of Planescape and its Elemental, Quasimental and Paraelemental Planes, its Primordials were a very diverse bunch, with figures like Atropus (imagine a frigging planet made of undead flesh 'n' bone and you got the right idea), Iktha-Lau (embodiment of deep space and the empty void) and Maul-tar (a freaking huge-ass dragon-thing of stormclouds and lightning chained down by rune-etched chains with links the size of castles).