Although Equestria is a place of peace and prosperity under the rule of Princess Celestia and Princess Luna, there is never any mention of ancient Equestrian history. It isn't taught in schools. There are no books on the subject. Not even the myths or beliefs have survived the test of time. The earliest historical records begin with the story of Hearth's Warming Eve, yet civilization was already present then. When Twilight stumbles across an ancient history book, many dark secrets come to light.