Arthur Maxson

 is the last descendant of the Maxson dynasty in the year 2277, the founders and traditional leaders of the Brotherhood of Steel.

Background
He was born in 2267 to Jonathan and Jessica who are both deceased by 2277. Still a child and ranked as Squire, he has been placed under the supervision of Elder Owyn Lyons. Due to internal conflicts in the Brotherhood of Steel this move was thought to increase his personal safety; he is considered to be safer in the Citadel than in the Brotherhood's homelands, even though it is located in enemy territory.

From his computer (which you can hack without Karma penalties), you can find that he writes stories, has a crush on Sarah Lyons (because she taught him to kill a man by stabbing the man in the kidneys), and that there is a Guns and Bullets magazine underneath a bed in the den.

Also, if you talk to him and ask, "Do they make you fight?" He will say that he accidentally shot Sarah Lyons and says, "It was just a flesh wound".

Daily schedule
He can usually be found in the Citadel's B-Ring where his room (and personal terminal) is located.

Interactions with the player character
Other then being able to be talked to by the PC he serves no other purpose.

Appearances
Squire appears only in Fallout 3.

Behind the scenes
is likely a recreation of Arthur Pendragon (King Arthur). He is the rightful heir to the Brotherhood of Steel, but has been sent to live with a foster father for his safety. His Kingdom is divided and the factions cannot agree upon a leader. Arthur Maxson is being trained in the ideal of might for right, which his Kingdom has never followed.

Also, if you talk to him and ask, "Do they make you fight?" He will say that he accidentally shot Sarah Lyons and says, "It was just a flesh wound", a possible tenuous reference to Monty Python and the Holy Grail.