Origin of the Primals

[Jandor]

Ifrit is hinted to have been created way back in Ancient times by Lahabrea, way back before the sundering the player characters past self "borrowed" Ifrita to deal with a volcano. Short story here.

Garuda was the Allagan commander in charge of the Ixal troops they created, if I recall correctly.

Titan doesn't have any proper or even hinted backstory, again, as far as I can recall anyway.