We Want Epic Lootz
Long ago, the world was twinned to save it from a final conflict between gods and primordials. The gods took one sibling (Toril), and the primordials claimed the other (Abeir).
Ages later, the Spellplague (which Abeirans call the Blue Breath of Change) caused the two separate worlds to collide and overlap. Portions of each world shifted into the other. Then the worlds separated again, contact severed, but each having contributed to the other. Perhaps as much as one-quarter of Toril now hosts lands native to Abeir.
The two most significant transplanted lands on the continent of Faerûn are Akanûl and Tymanther. However, the largest new landmass by far is an entire continent that Faerûnians call Returned Abeir, which lies west of the Trackless Sea.
In Returned Abeir, dragons rule vast realms of slaves. The dragonborn are the most numerous, but they are given to rebellion. Dwarves and humans are plentiful. Genasi were also numerous, but mostly on the eastern continent of Shyr (a continent that was not transported to Toril by the Blue Breath of Change). Other races are less numerous, and fey such as elves and eladrin are rare curiosities introduced only in the last century. Organized religion in Returned Abeir (faiths, simple shrines, and traveling clergy) is something new; even the concept of gods who answer prayers is still alien to many, though some deities of Toril have set their sights on the returned lands.
- pg. 200 of Forgotten Realms Campaign Guide by WotC