Suramar is an ancient elven empire that was formed over ten thousand years ago. Since the War of the Ancients, Suramar has been led by the Grand Magistrix Elisande. Just prior to the Great Sundering after the War of the Ancients, a barrier was formed over Suramar City, the nation's capital, to protect the night elves of Suramar. Because they saw no moonlight and relied heavily upon the power of the Nightwell, the night elves of Suramar evolved into Nightborne, the Shal'dorei.
During the Burning Legion's third invasion of Azeroth, Gul'dan appeared to Elisande, saying that the Burning Legion demanded the Nightwell for their lives, and that they had three days to make their decision. Elisande gave the Nightwell over to the Legion and brought down the barrier, which led to rebellion among the Nightborne.