"Just over a thousand years ago, Princess Cadence, then known as Queen Cadence of the Crystal Empire, was the pegasus ruler of the land, heir to the throne in a long line of previous queens. Her partner, but not lover, Sombra, was the unicorn ruler. The Crystal Empire had always been led by a king and a queen; a unicorn and a pegasus. It represented balance, to them, since no earth ponies had lived in the Empire so long ago. Their compassion as rulers, doubled via their loving subjects, fed the Crystal Heart and kept its Magic sustained."

"Wait, Celestia, King Sombra actually used to be king of the Empire?" Twilight asked, more than slightly shocked.

"Of course, Twilight. The reason for your doubts, however..." Celestia began.

"But Sombra grew weary of the constant demands of being a leader. He began to long for the power of a ruler with far less accountability. He began to desire to be a dictator, just so that he could skip the politics and get straight to the power. Sombra began experimenting with Hate Magic. It twisted him, forcing him to become a monster rather than a mere pony. He lashed out at Cadence, and sealed her within the Crystal Heart. It was there that she became an Alicorn; the sentient Love Magic within the Heart awoke her dormant power, transforming her mortal body into that of an Alicorn so that she could continue living. Her Cutie Mark looks like the Heart for this very reason; it used to be just the golden laurel signifying leadership."

"Magic can change Cutie Marks?!" Twilight shouted, completely bewildered. "But I thought that Cutie Marks were permanent!"

"Twilight, if you'll recall, Cadence's Mark still has the golden laurels wrapped around the Heart. It added, not subtracted, from her Cutie Mark. As you might also know, Cutie Marks are given by Magic. They can be altered by Magic as well, though they can never be taken away," Celestia explained, worried at the strange look her student was giving her.

"I...I guess that makes sense..." Twilight stuttered, still somewhat at a loss. "Continue, please..."

"After Sombra took over the Empire and sealed Cadence, my sister and I caught word of it from a crystal pony refugee. He explained that Sombra had gone mad with power, and Cadence was 'indisposed' at the time. By the time Luna and I arrived at the Empire, dark crystals of Hate Magic had grown all over the citadel, and the crystal ponies had been enslaved. We fought long and hard, and I almost fell to Sombra's evil Illusions -- Luna wasn't nearly as susceptible, and snapped me out of my fears -- before we combined our Alicorn Magic to Banish Sombra for...well...we didn't really know how long it would be, but we knew in our hearts that he would be no trouble for a long time. As soon as his power was dispelled, Cadence was freed from the Heart. However, a portion of his Dark energy remained, and it managed to cast a Time Lock spell on the entire Empire. Cadence barely escaped in time, and she came to live with us in Canterlot, wracked with grief for her Time-Locked subjects. "

"Wait, you said this was just over a thousand years ago. I know it was recently that the Empire returned and Sombra was completely destroyed. But, a thousand years ago, you also had to seal Luna on the moon as Nightmare Moon. When did that happen? Was it before or after the Crystal Empire incident?" Twilight asked, still attempting to grasp Celestia's timeline.

Celestia gave her a knowing smile, causing Twilight to groan. "Next chapter?" she asked.

"Next chapter," Celestia answered. Next Chapter: 6: The Nightmare Estimated time remaining: 13 Minutes