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. A blurb on one of the toy sets based around the Empire says that Princess Cadance and Shining Armor "lead the Crystal Empire together!" In The Ballad of the Crystal Empire song, it stated that the Empire has a "Crystal Kingdom Anthem". Its anthem has yet to be heard in the series.

Depiction in the series
The Crystal Empire first appears in the third season's opening two-parter The Crystal Empire, having "suddenly appeared in the arctic north of Equestria after a 1,000-year curse caused it to vanish" according to the respective descriptions of the Adventures in the Crystal Empire DVD by Shout! Factory and a clip from The Crystal Empire - Part 1 uploaded by The Hub's YouTube channel. It is inhabited by Crystal Ponies and tiny ewes, and is described in the Ballad of the Crystal Ponies as having a rich culture and long history, including "the Crystal Kingdom anthem". Local food 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 unicorn, King Sombra, who turned it into a dark land and enslaved the crystal 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, causing 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 barrier around it.

Celestia also sends Twilight Sparkle and her friends 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 Fair. Twilight uses her magic to carve a local crystal 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, so while the others keep the crystal 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 power, Sombra begins to cover the empire with shadow crystals. Twilight and Spike search the castle for the Crystal Heart, as 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, causing Sombra to trap Twilight inside a wall of shadow crystals. 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, and 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 crystal ponies. 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 Armor, Spike and the main six into crystal ponies and destroy Sombra along with his shadow crystals.

The population consists of earth 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 Rarity's eye design.

The Crystal Empire is symbolized 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 main six arrive. The Cutie Mark Crusaders stand in front of a gift shop selling Crystal Empire castle snow globes.

In Games Ponies Play, Twilight and her friends visit the Crystal Empire to welcome the Equestria 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 My Little Pony Equestria Girls, the Crystal Empire is the venue for a "princess summit". During this time, Sunset Shimmer uses a magic mirror (that once resided in Canterlot Castle, but was moved to the Crystal Castle) to sneak into Twilight Sparkle's room to steal the element of magic.

Other depictions
The Crystal Empire is the focus of a toy line of the same name. This toy line has a logo featuring Princess Cadance and a description reading, "Welcome to the CRYSTAL EMPIRE, a magical place full of hidden secrets! The ponies shine and sparkle here!" Crystal Fashion Style Princess Cadance & Shining Armor, one of the toy sets included in this toy line, has an individual description reading, "PRINCESS CADANCE and SHINING ARMOR share a big responsibility! They lead the CRYSTAL EMPIRE together!" The Crystal Princess Ponies Collection, another one of the toy sets included in this toy line, has an individual description reading, "PRINCESS CELESTIA and PRINCESS LUNA believe that PRINCESS CADANCE will bring happiness to the CRYSTAL EMPIRE!" Fluttershy, a single toy to be included in this toy line, has an individual description reading, "FLUTTERSHY has a tea party to make friends with the CRYSTAL EMPIRE ponies—they seem just as shy as her!" "Crystal Empire" is also listed on the packaging of mystery pack waves six and seven.

The My Little Pony Wedding Quiz section of Hasbro's Pony Wedding microsite describes the Crystal Empire as "cultured".