Once upon a time, before Celestia and Luna there was a pony called Chrysalis who was running to be the next ruler of the land of Equestria. She had her dream of becoming the best ruler possible and to be loved by her subjects. Things went well until for a long time she became corrupted and evilness took her over. She made a potion for herself to make her powers stronger. She started treating her subjects horribly and became a danger for her own land. Due to the outbreak of her corruption she was exiled from her own kingdom along with some of her subjects and had to live under the radar. She continued developing her own kingdom outside the boundaries of Equestria and one day a 1,000 years later she striked back to finish what she started and regain control of the land which was hers a while ago. And thus the plot for the “Canterlot Wedding”episode began.