Equestria sat in a powerful position as it neared the end of the fourth age. It was the most powerful empire on the face of the planet. Its armies were vast and powerful. Its rulers controlled the cycle of night and day. But…all was not well.

The destruction of The Crystal Empire early on in the fourth age was the princesses' most noteworthy embarrassment. With the destruction of the Crystal Empire by their own hooves and the dirty tricks of King Sombra, they were forced to adopt Cadence, a pegasus and the only remaining royal family member, and absorb the remains of the empire into their own.

Now, near the end of the fourth age, after the battles with the gryphons, with their borders secured and their position as a superpower sealed, the two sisters turned their attention to find a way to bring the Crystal Empire back. One of the sisters would toy with a magic far more insidious than she could possibly know. This would set off a chain of events that would pit brother against brother, father against son. This would mark the end of the fourth age and the beginning of…

The Equestrian Civil War


Note: Based on Bloodpool's awesome head-canon.