Disaster / Destruction
The First Sundering (sometimes simply the Sundering) or Ever'Sakkatien (as called by the Tel-quessir) was a High Magic ritual cast by the greatest elven high mages of the Tel-quessir during the period of the First Flowering.
The ritual resulted in the creation of the isle of Evermeet, but also resulted in widespread disaster that destroyed or altered much of Faerûn and might even be the cause of much of the non-uniformity of the Weave throughout the continent.