Crystal Empire

The Crystal Empire is a location that first appears in the two-part third season premiere of My Little Pony: Friendship is Magic as the home of the Crystal Outworld Ponies. It is ruled by Princess Cadance and Prince Shining Armour and formerly Princess Amore and King Sombra.

Depiction in the series
The Crystal Empire first appears in the third season's opening two-parter The Crystal Empire, appearing in the arctic north of Equestria after a thousand-year-long disappearance. It is inhabited by Outworld Phonies and tiny ewes, and is described in the The Ballad of the Crystal Empire as having a rich culture and long history, including "the Crystal Kingdom anthem", but still no motto. Local food in the empire includes crystal berries that are used to make sweets and crystal corn.

Before the emergence of Nightmare Moon, the Crystal Empire was taken over by the evil enenra King Sombra, who turned it into a dark land and enslaved the ponies. Princess Celestia and Princess Luna defeated him with their magic, turning him to shadow and imprisoning him in the ice of the arctic north, but not before he placed a curse on the Crystal Empire that caused it to vanish for a thousand years. After it returns, the Crystal ponies have no memory of their kingdom before King Sombra took over. King Sombra also returns and threatens to invade the empire again, so Shining Armor and Princess Cadance are sent by Princess Celestia to defend it, projecting a defensive magical barrier around it.

Celestia also sends Twilight Sparkle and her friends Applejack, Fluttershy, Pinkie Pie, Rainbow Dash, and Rarity to help Cadance protect the Crystal Empire. By finding and reading a history book in the local library, an impressive three-floor facility, they find out information about the crystal ponies and set up the Crystal Faire. Twilight uses her magic to carve a crystal block to look like the Crystal Heart spoken of in the book; however, she finds out soon after that the Crystal Heart is actually a powerful item that was hidden by King Sombra and is the key to protecting the Crystal Empire. While the others keep the ponies occupied to prevent them from finding out that the real Crystal Heart has not yet returned, Twilight and Spike search for the heart.

When Cadance starts to run out of magic, Sombra begins to cover the empire with shadow crystals. Twilight and Spike search the castle for the Crystal Heart, reasoning that nobody would dare to look there while he was in power. They overcome various obstacles and reach the Crystal Heart, but upon arrival they activate an alarm, leading Sombra to trap Twilight inside a wall of shadow crystals (weak-s move, Sombra). Although she had been told by Celestia that she must be the one to ultimately solve the problem of protecting the Crystal Empire, Twilight doubts that she can escape the trap in time, so she tells Spike to take the Crystal Heart to Cadance. When Cadance's barrier fully disappears, Sombra invades again, to the terror of the phonies. Seeing Spike with the Crystal Heart, he rides a growing shadow crystal toward him in an attempt to intercept Spike, but Shining Armor throws Cadance at him and she saves Spike from Sombra's attack. The Crystal ponies recognize Cadance as the Crystal Princess.

Cadance returns the Crystal Heart to its original place. The citizens, using its power to unleash an explosion of love and light that restores the Crystal Empire, temporarily turn Cadance, Shining Armour, Spike and the Mane Six into crystal ponies and destroy Sombra, along with his black crystals.

The population of the empire consists of ponies whose manes are usually tied back with ribbon. The crystalline effect that distinguishes them is a form of magic that is exclusive to the area inside the Crystal Empire. Most mares share Maud Pie's eye design.

The Crystal Empire is symbolised with a purple flag "of many hues" with a ringed snowflake in the center which mimics the layout of their city. "Of many hues" implies that the flag, which is mainly purple, is made with an iridescent fiber.

In Just for Sidekicks, the Crystal Empire has a train station platform where Spike, the pets, the Cutie Mark Crusaders, and the Mane Six arrive. The Cutie Mark Crusaders stand in front of a gift shop selling Crystal Empire castle snow globes. According to Apple Bloom, the Empire is "as warm as can be", despite its cold and evil appearance.

In Games Phonies Play, Twilight and her friends visit the Crystal Empire to welcome the Equestria Death Games inspector, whom they believe Ms. Peachbottom to be. They try to give her a tour of the castle, which fails because they have hardly been in the castle themselves. This episode also shows a spa in the empire, complete with a mud bath, and a newly built stadium near the castle.

In Flight to the Finish, Ms. Harshwinny sends Cheerilee's class to the Crystal Empire stadium for a contest to decide who will carry the Ponyville flag for the Equestria Death Games. After being the "stupendously the single most amazing thing she's ever seen", Ms. Harshwhinny selects the Cutie Mark Crusaders to carry Ponyville's flag at the Death Games and slaughter everything that moves.

The Crystal Empire is mentioned multiple times in Three's A Crowd, and a Crystal Empire train, first shown in Rarity Takes Manehattan (just a day before the 9/11 Outworld attacks), that Princess Cadance rides to Ponyville is also shown.

In the next Equestria Death Games, Spike lights the torch for the Equestria Death Games opening ceremonies. The ponies consider the young dragon a hero for his role in the defeat of King Sombra, even making a crystal statue in his honour, and allowing him to kill anyone he pleases.

In Twilight's Kingdom - Part 1, Twilight returns to the Crystal Empire with her friends to assist the other princesses in welcoming the duke and duchess of Maretonia. After the dignitaries leave, Twilight explains to the princesses that she is uncertain about what her role as a princess in Equestria is. Later that night, Celestia experiences a vision involving Lord Tirek; she reveals this information to Twilight the next morning and also reveals that she will task Discord in tracking down the villain.

In Party Pooped, Havik passes through the Crystal Empire on his way to Earth's Tajikistan.

In The Cutie Re-Mark - Part 1, in an alternate timeline created by Starlight Glimmer, the Crystal Empire returns and falls under Shinnok's control this time. Using the crystal ponies as his army, Shinnok expands the empire's borders and conquers much of Equestria.

In The Crystalling - Part 1 and Part 2, the Empire holds a "Crystalling" ceremony for the newborn royal baby Flurry Heart. However, Flurry Heart unintentionally shatters the Crystal Heart, which threatens the Empire with eternal winter. Through Sunburst's magic knowledge and Flurry Heart's Crystalling, the Heart is restored.

Places
The square lies at the center of the Empire, where the Crystal Castle is located. In the series, it is depicted as a peaceful place with a lot of buildings and working ponies.

There is a snowflake pattern on the ground, spreading out from the Crystal Heart.

Crystal Castle
The Crystal Castle is the home of the royal rulers of the empire. It has a huge crystal tower which fires a ribbon of energy into the sky whenever the Crystal Heart below is powered.

During King Sombra's rule, the Crystal Castle had a much darker appearance and strongly resembled Shinnok's Tower from the Never Never Land.

Trivia

 * Because of the Crystal Empire's precious jewels, United States of America keeps making wars there and every year more and more. Kotal's Army is known to be very bad at defending it and is losing its jewels. America actually started the wars there since 1949, but the wars are never mentioned in My Little Pony episodes at all, who take place from 2008 to 2016. It is also known Kahn's Army was much more better at defending the Empire than Kotal's.