Caesar's Legion

Ceasar's Legion is a faction from the American midwest modelled after ancient Romans and probably led by a man called Caesar. One of their ranks is called Vexillarius. Not much is known about them aside from that, but they probably waged war to gather slaves and wealth like all Romans tend to do, and they have been known to fight the forces of the tribal "goddess" called Hecate. The Hanged Man also had some ties to the Legion. One of the Legion's outposts was located in Denver.

Denver camp
The Denver Legionnaires are camped out in a hotel in south Denver with some slaves they've rounded up. Every couple of weeks they send a pair of fast guys out east to see if the radioactive dust storms have subsided for the season. Once they do, they'll head out.

They have the lower floors secured with chain link fence and barriers made of junk. They keep the dogs away with chemical repellant sprayed in the area (resprayed every year when they return here). They're well-armed (as far as wastelanders go) and alert. They stay on the 2nd level, though they are watching their surroundings (they'll be alert to your arrival unless you manage to sneak your way in) and might have a sniper hiding out on the ground floor. They keep the slaves locked in rooms on the 2nd and 3rd floor.

Appearances in games
The Legion was initially (when Chris Avellone still worked on the project) to play a significant role in Van Buren (Black Isle's Fallout 3), but they were mostly cut out because the game was getting too big, although they had some minor appearances in the game. Black Isle planned to give them a major role to play in Fallout 4. It is not certain if they will appear in any future Fallout game.