Depiction
When Palpatine becomes chancellor of the Galactic Republic, he phases out the Senate Guards in preference for his own Royal Guards. Once Palpatine creates the Galactic Empire with himself as Emperor, the Royal Guards accompany him at all times. Guardsman Kir Kanos is the anti-hero in Dark Horse's Crimson Empire comics.
Royal Guards are chosen from among the Empire's stormtroopers, and Guards regularly cycle back into the stormtrooper corps to maintain their battle readiness. Candidates for Royal Guard training are evaluated for their size, strength, intelligence, and loyalty; those chosen for training are assessed for their combat reflexes and stamina, and they receive training in a wide range of armed and unarmed combat. Guards' crimson robes conceal armor more advanced than stormtrooper armor.
Read more about this topic: Emperor's Royal Guard