After Twilight is crowned by Celestia and Luna as the sole princess of Equestria and left to govern the land by herself, Equestria is thrown into an armed conflict with the Griffon Nation. While necessary measures are undertaken to ensure Equestria's security, these measures along with the war effort sow the seeds of discontent. This discontent soon boils over into a full-scale revolt that threatens the very throne upon which Twilight sits.