Much is whispered but little is known of the terrible creatures called the First Ones. Believed to have been fashioned by the Primordials before the Gods, the First Ones were banished from Creation before the Dawn War. They took refuge in the darkness of the void, a place now known as the Far Realm, a nightmare country none have visited and returned from whole.
During the time of the the Long Night, the First Ones returned and doused the light of the sun, plunging the world into endless night. They attacked the Gods and the Primordials equally, but the Gods capitalized on the chaos they caused to rally against the Primordials. After the Primordials were defeated, the First Ones were driven away again as Sunastien relighted the sun with his own power.
Many of the First Ones returned to the Far Realm, but others slithered into the dark places of the world, especially the depths of the Underdark. They represent every manner of madness and horror, and their manner of being is known as the aberrant. Mind flayers, aboleths, and beholders are among these horrid beings, but there are many others. The goals of the First Ones are unknown, possibly unknowable, but they seem to seethe with hatred of the younger races. There is strong evidence that the First Ones were among those that influenced the Tieflings of Bael Turath in the Ruined Empire, and some contend that dark and star pact warlocks make their bargains with representatives of the First Ones.