The Sundering
The Sundering was an event in the Forgotten Realms that stemmed from WoTC struggling desperately to try and win back the crowd after the immense negative feedback to the changes they had made to Faerun with the Spellplague.
Its name stems from the fact it centers on the twin plants of Abeir and Toril pulling away from each other, which somehow not only replaced the continents that had gotten switched around, but magically made everything go back to more-or-less 3rd edition status quo, including bringing back all of Drizzt's dead friends and re-empowering Elminster.