Changeling assault on Equestria
The Changeling assault on Equestria was a campaign in which the Changelings under Queen Chrysalis simultaneously attacked several locations across Equestria. The exact timing is unclear, but it seems to have occurred some time before the birth of Flurry Heart and the subsequent reformation of the Changelings.
History
Changeling forces are known to have attacked both the Crystal Empire and Ponyville, though for once they seem to have spared Canterlot, which was defended by Princess Celestia and Princess Luna. A pair of Changelings were sent to prevent Rainbow Dash from joining forces with the other Wonderbolts, who had been summoned to go to the aid of the Crystal Empire. Taking the forms of two of the Shadowbolts, they challenged her to a race but were fairly easily defeated by the Pegasus. In the Crystal Empire, meanwhile, the Crystal Guard engaged attacking Changelings while waiting on assistance from Canterlot.
Forced to remain inside the Crystal Castle, Shining Armor searched the castle library and discovered the existence of a hidden arsenal created by Princess Amore and hidden in the Crystal Caverns beneath the castle. Entering the caverns, he passed a magical test prepared by the long gone princess and gained access to the arsenal, but found only one potion to still be viable after many years of abandonment. The Wonderbolts-minus Rainbow Dash-promptly arrived by prototype sonic gliders and helped to drive off the Changelings invading the Empire. When it became clear that the Changelings were mounting a massive assault on Ponyville, Shining Armor rushed there in order to deliver the potion to Twilight Sparkle.
Ponyville had already suffered some Changeling infiltrations, with Cheese Sandwich and Lyra Heartstrings being among the ponies to be abducted and/or impersonated. Pinkie Pie saved Cheese Sandwich, and the pair worked together to drive off several Changelings, while Twilight and the real Lyra came to the aid of Bon Bon when she was terrorized by the impostor Lyra. As the trio made their way to the Castle of Friendship, the Cutie Map summoned Twilight, sending her to a previously unvisited room at the top of the castle. Twilight and her two companions proved to be just the ponies needed to open the magically sealed door, and they entered the chamber beyond to find the Armor of Friendship.
Equipped with the armor, Twilight was able to identify disguised Changelings and capture them, but soon regrouped with the rest of the Mane Six to address the incoming Changeling force led by Chrysalis herself. Shining Armor arrived with the potion, which Twilight sampled and thus gained the ability to outfit her brother and friends with magical armor. Despite this, the Changelings proved too numerous, and victory was only achieved when Twilight acted on Spike's urgings to use the potion on him. Spike thus grew into an adult, armored version of himself, and proved too formidable in this form for the Changelings to imitate or overcome. The Changelings were thus forced to retreat, leaving Equestria at peace for the time being.
