Brotherhood - Enclave War The Brotherhood - Enclave War was a military conflict in 2277 between the Brotherhood of Steel and the Enclave . Prelude . When the Brotherhood arrived in the Columbia Commonwealth area in 2255 , they did not yet know that the Enclave , who were defeated by the California chapter of the Brotherhood and the New California Republic sixteen years ago , had fled to the Columbia Commonwealth ( Capital Wasteland ) , establishing a headquarters at the pre - war U . S military installation Raven Rock . Under the leadership of Elder Owyn Lyons the Brotherhood began combating the local super mutants , unaware of the rebuilding Enclave . War . In 2257 , the Enclave commenced an indirect propaganda campaign against the Brotherhood . The Enclave , now under the leadership of President John Henry Eden , plotted in secret at Raven Rock . For twenty years , there was no interaction between the two factions , leading many to suspect that the Enclave radio broadcasts were on an old loop . However , in 2277 , Colonel Augustus Autumn led an attack on the Jefferson Memorial , and took over Project Purity , as part of their plan to " purify " the wasteland . James was among those killed , but the Lone Wanderer and other survivors escaped to the Citadel . The Brotherhood Outcasts were also attacked by the Enclave on patrols . Occasionally , the Outcasts would also launch attacks against the Enclave , but these were fairly unorganized . Protector Henry Casdin largely left the Outcasts out of the war . After the capture of the Jefferson Memorial , the Enclave began their conquest of the Capital Wasteland , establishing many small outposts throughout the region . They even tried to annex Vault 101 , only to be denied entry by its isolationist overseer . The Brotherhood set out on collecting evidence that Project Purity could function , in order for them to reclaim the Memorial . The Enclave caught onto this , kidnapping the Lone Wanderer in Vault 87 and confiscating the G . E . C . K . . The Lone Wanderer awoke in captivity inside Raven Rock and was interrogated by Colonel Autumn . President Eden then distracted Autumn and sent him elsewhere , summoning the Lone Wanderer to his office . It was here that the President was revealed to be a ZAX supercomputer . The former recruited the Lone Wanderer to act on his behalf , giving them a vial of Modified FEV to insert into the purifier which would cleanse the wasteland of all life forms that had been exposed to too much radiation . Eden then facilitated their departure from Raven Rock . After the Brotherhood received word that the Enclave possessed the means to activate the purifier , they launched an offensive to reclaim the Memorial with the support of Liberty Prime . The Brotherhood forces and the Lone Wanderer stormed the memorial and confronted Colonel Autumn , although his fate is not known . The purifier was then started . Two weeks later , the Brotherhood started delivering the water throughout the wasteland . The Enclave , after its defeat , made a last stand at Adams Air Force Base . When the Brotherhood invaded the Enclave ' s satellite relay station , the base was destroyed , but Liberty Prime was also eliminated by an orbital missile strike , a major blow for the Brotherhood . The Lone Wanderer scoured the ruins of Old Olney to retrieve a Tesla coil to assist in the scribes ' research in Tesla cannons - the Brotherhood ' s last chance of countering the Enclave ' s VB - 02 Vertibird s . After creating the Tesla cannon s , they launched a final attack on Adams AFB . The Enclave put up a tenacious final stand , but were ultimately annihilated by the Brotherhood ' s forces . The launch terminal for the Bradley - Hercules orbital satellite indicates that the Enclave had given themselves the means to eradicate the settlements of Megaton and Rivet City . They also had Project Purity and the Citadel selected as potential targets . The Lone Wanderer can target Adams ' mobile base crawler and decimate the Enclave . ( Alternatively , the Citadel can be targeted resulting in the destruction of both the Brotherhood ' s headquarters and the majority of their forces in the Capital Wasteland , as well as the destruction of the Enclave at Adams Air Force Base ) . In " Fallout 4 " , it is confirmed that the Brotherhood of Steel have taken control over Adams Air Force Base , the Enclave ' s mobile base crawler having been destroyed . As a result of this , the Brotherhood has gained access to all of the facility ' s spoils of war . Aftermath . The Brotherhood of Steel would win the war against the Enclave in the east , their mobile base crawler being destroyed by the actions of the Lone Wanderer ; its destruction being a decisive blow . Adams Air Force Base would become a major staging area for the Brotherhood where they would construct the airship Prydwen from recovered Enclave technology , a process which would take a total of 8 years . As well as this , the Brotherhood now had access to what remained of the Enclave ' s VB - 02 Vertibird fleet , upgrading them for transit aboard their newly built airship . The Maxson bloodline would continue into the late 23rd century , as Arthur Maxson is alive by 2287 ; now commanding the rank of Elder of the Brotherhood of Steel in the east . That same year , he would mobilize part of his forces and carry out an expedition north towards the Commonwealth , with the aim of destroying the Institute , discovered by Brotherhood recon teams sent into the ruins of Massachusetts previously . The expedition to the Commonwealth was made possible largely in part to technology recovered from the war with the Enclave ; namely access to Vertibird gunships as well as other resources re - purposed to build the Prydwen , the pride of Maxson ' s Brotherhood of Steel .