The world of Elyziæ was created by Caellus during Primonavea, though it was still shapeless at that point in time. It were the Primunati who used the elements to shape the world. The process of shaping lasted the entire Era of the Moon and ended when the Secunati were born.
The only major changes to the dominions were made during the Dissonance's, where all the dominions had certain parts either broken off from the main ladnmass, or sanked all together. Most famous is the Ruins of Domècus—where once the beating heart of the Aurum Imperium resided, is now a strait seperating Tearithia and Sautrin.