Brotherhood Civil War

The Brotherhood Civil War was a conflict between the Brotherhood of Steel and a splinter group, the Outcasts. The conflict began in 2276, Following a drastic shift in mission profile by Owyn Lyons, a large group of Brotherhood loyalists broke off from Lyons' chapter, forming their own: the Outcasts.

Background
 As Owyn Lyons slowly changed the profile of the mission to DC, from gathering and processing pre-War technology to endeavours he considered beneficial to the local populace, discontent began to rise among his ranks. The dissatisfaction reached a boiling point in 2276 when Paladin Henry Casdin openly defied the Elder's orders and rallying his followers, secured large amounts of weapons and equipment and simply left the Citadel.  Branded as outcasts and struck from the Codex, loyalists reformed into a new chapter, bearing the name Outcasts as a badge of merit, along with the black/red paint-job on their powered armors. They secured a new base of operations, in Fort Independence near the ruined city of Fairfax and restarted their original mission of securing technology.

Development
The Outcasts have many advantages over Lyons' forces: when departing the Citadel, they took a large part of supplies and military ordnance with them, leaving the rogue chapter in a critical condition. Furthermore, the loyalists are all veterans of years of warfare and wasteland travels and as such have an edge over Owyn Lyons' forces, which represent a mix of original Brotherhood members and hastily trained local recruits.

Despite the advantage, Outcasts do not seek to exploit their advantage and refuse to openly attack Lyons' forces. They focus on their mission and their long range patrols in search of lost technology make the wasteland much more secure, as they exterminate any threats with extreme prejudice, but do not engage non-hostile humans unprovoked.

However, if confronted with a Brotherhood patrol, the Outcasts will attack and fight until either side is dead. The frequency of these encounters increased after Project Purity went online in 2278 and the Brotherhood of Steel began assisting with Aqua Pura deliveries across the Capital Wasteland, thus taking them into territory held by the Outcasts.

Legacy
Though the outcome of this civil war is unknown, it was notable enough to gain the attention of the Western Brotherhood chapters, though they, themselves, took no action. Veronica, a scribe in the Mojave chapter, will comment about the conflict four years later.