Royal guards

The royal guards are a group of white and dark gray Pegasus, unicorn, and Earth pony stallions clad in solid gold (sometimes with purple paint) who serve Princess Celestia and Princess Luna. They act as bodyguards for the princesses, ceremonial guards in festivities, and chauffeurs in several occasions. The guards' helmet crests are reminiscent of Greek Corinthian helmets and medieval Barbuts Helmets, and are also the same color as their tails and mane. The guards are generally shown wearing extremely serious expressions and almost never speak, but when they do, their voice is provided by Jayson Thiessen or Andrew Francis. Their cutie marks are obscured by their uniforms.

Unicorn guards
The unicorn guards first appear in the show's title sequence, standing at the feet of Princess Celestia's throne. Their next appearance is in The Cutie Mark Chronicles. Set in Twilight Sparkle's flashback, eight gray unicorn guards play fanfare for Princess Celestia as she comes on stage and raises the sun for the Summer Sun Celebration. The guards remain expressionless throughout the ceremony. They stand at the aisles of the theater in Hearth's Warming Eve.

They have more active roles in two episodes: They guard the VIP balcony and allow Rarity to enter it at the Wonderbolts race in the episode Sweet and Elite, where the color of their magical glow is green.

Unicorn Guards appear in It's About Time wearing different uniforms, featuring helmets with flowing crests and redesigned armor. They patrol the Canterlot Archives and one of them, who recognizes Twilight Sparkle, unlocks the restricted "Star Swirl the Bearded" wing for her, even though at first she tries to avoid them and dreads being discovered sneaking about but finds herself eventually cornered.

Many unicorn guards of multiple colors appear in A Canterlot Wedding - Part 1 and A Canterlot Wedding - Part 2.

Celestia's Pegasus guards
During the first episode, a pair of the more commonly seen white-coat Pegasus guards chauffeur Twilight Sparkle and Spike from Canterlot to Ponyville in a flying chariot. Their following appearance is in the second episode, when the Mayor commands three of them to stop Night Mare Moon, she strikes them with lightning bolts to swat them away. The guards later draw the royal chariot into town at the end of the episode. They briefly appear in Swarm of the Century, driving Celestia's flying chariot, and in Sonic Rainboom, accompanying Celestia in her spectator box at Cloudsdale's stadium.

They make their only speaking appearance in A Bird in the Hoof, where they guard the Princess and search for her pet bird, Philomena. Two guards stand on duty at the entrance to Sugarcube Corner where Celestia is staying. They are pestered by Rainbow Dash who tries to elicit a response from them, but they remain stoic and silent. Soon afterwards, they hinder Fluttershy's entrance until Twilight confirms she's allowed inside. Later, a guard notifies Celestia that the mayor seeks an audience with her. Even later, two guards are sent to inform Twilight that the Princess's bird is missing, and they continue looking for the bird throughout the episode. The episode ends with the bird tickling the guards and making them laugh at Rainbow Dash's request.

Many Pegasus guards of multiple colors appear in A Canterlot Wedding - Part 1 and A Canterlot Wedding - Part 2.

Hearth's Warming Eve guards
The Pegasus guards featured in the Hearth's Warming Eve pageant share the same design as Celestia's Pegasus guards, but have a different color scheme and a lightning bolt emblem instead of a star-shaped emblem.

Luna's Pegasus guards
Princess Luna's Pegasus guards appear in Luna Eclipsed, chauffeuring her flying carriage to Ponyville. They have a dark gray coat, black tails, tufts of hair on the tips of their ears, bat-like wings, and cat-like slit pupils. Their armor is purple, and it has a webbed crest over the helm. One of her guards appears in the Castle Creator game.

Earth pony guards
Two of the royal guards seen overlooking the station in A Canterlot Wedding - Part 1 have no wings or a horn, marking them as Earth pony guards. Another Earth pony guard appears in The Crystal Empire - Part 1, informing Princess Celestia about the return of the Crystal Empire, this also marks the first time in the series that a Royal Guard has removed his helmet, confirming at least for the Guard in question that the crest on their helmet matches their mane color.

Shining Armor
Shining Armor is introduced as the Captain of the Royal Guards in A Canterlot Wedding - Part 1. He is the older brother of Twilight Sparkle and husband of Princess Cadance. Caramel, Cherry Fizzy, Noteworthy, and Meadow Song serve closely to Shining Armor in A Canterlot Wedding - Part 2.

My Little Pony mobile game description
Royal Guard:

The Royal Guard pegasus ponies serve as the protectors of Princess Celestia and all of Equestria.

Princess Luna's Royal Guard:

Princess Luna's protector ponies are identified by their dark coats and manes, as well as their purple armor.

Quotes
"Halt!"

- Pegasus guard in A Bird in the Hoof

"Who goes there?!"

- Pegasus guard in A Bird in the Hoof

"We were told we could find Twilight Sparkle here."

- Pegasus guard in A Bird in the Hoof

"We regret to inform you Miss but the royal pet has gone missing."

- Pegasus guard in A Bird in the Hoof

"Hey, Twilight, haven't seen you in a while. Let me open that for ya."

- Unicorn guard in It's About Time

"News from Northern Equestria! Uh... Your Highness."

- Earth pony guard in The Crystal Empire - Part 1

"I am simply to tell you that it has returned."

- Earth pony guard in The Crystal Empire - Part 1