The Empire does not trust the security of it's ruler to just any standard security force. They have the most deadly warriors in the galaxy at their command to protect the Emperor.
The Imperial Royal Guard. They wear cloaks of royal purple over red and purple armor that is more advanced then even power armor. It is form fitting to the user, protects against almost anything, and has a built-in cloaking device to ambush would be assassins. They are trained with every manner of weapon imaginable, but prefer to carry staves tipped with a four foot mono-molecular blade, as well as numerous concealed firearms and throwing blades. They have been augmented with genetic and cybernetic modifications to the point where they pretty much are not human anymore, with speed and reflexes beyond that of any human or alien. They are so deadly, that even the most legendary killers, bounty hunters, and soldiers in the galaxy give them the respect they deserve.
The elite strike forces of the Empire, the Imperial Knights are chosen from the best and brightest among the Imperial Military. They are then 'sponsored' to one of the Knightly Houses, Flame (Mechanized Infantry Combat Suit Unit) Spear (Forward Recon Unit), Air (Orbital Drop Assault), and Talon (Air/Space Combat). They are given the very best of everything, weapons, armor, and are only beaten in terms of protection by the Royal Guard.
The secondary part of being a Knight, is the ability to understand politics. Many Knights have retired and become sector governors, planetary leaders, or part of the various ruling bodies that make up the Empire's bureaucracy. They are expected to show perfect manners, and chivalry, at all times when out of combat. Cursing, losing control of one's anger, drunkenness, none are allowed by the Knights. They are a very close brotherhood of elite warriors, and are feared when sent to the battlefield.
When they are sent out to fight, the battle is always a victory. The Emperor has been sending them out far too often these days, and the harshness of his reprisals against unarmed settlements and supposed Rebel sympathizers has common people hating the Knights, while the upper class cozies up to them.
Intergalactic Blues
We are a literate sci-fi roleplaying guild