Geological / environmental event
Thousands of years after the rise of the great elven nations, hundreds of elf high mages united to cast a spell intended to create a glorious homeland for their race. The spell succeeded, but it rippled backward and forward in time, and the land was sundered, changing the face of the world. The largest continent of this new world is now called Faerûn. Far from its western shores rose the isle of Evermeet, considered a part of Arvandor, the home of the elven gods on the plane of Arborea, and a bridge between worlds.