Brotherhood of Steel (East Coast)

The East Coast Brotherhood of Steel is a division of the Brotherhood of Steel and was founded by Elder Owyn Lyons. Their headquarters is the Citadel, an imposing fortress built into and beneath the ruins of the Pentagon on the edge of what used to be Washington, D.C. As of 2287, they are led by Arthur Maxson, the last descendant of the venerated Maxson family line. Under his leadership, the Brotherhood has grown into a major military power in the region, able to project their power and influence all along the Eastern Seaboard.

History
Following the destruction of the Enclave on the West Coast, the Brotherhood dispatched an expedition to Washington, D.C. on a mission to reconnect with the Midwestern Brotherhood of Steel, investigate reports of super mutants in the Capital Wasteland, and recover any advanced technology. Led by Paladin Owyn Lyons, the group included Henry Casdin, Ishmael Ashur, Reginald Rothchild, and Lyons' 3-year-old daughter, Sarah.

Contact with the Midwest chapter was unsuccessful, so the group traveled to Pittsburgh. The city was being terrorized by wildmen, trogs, slavers, and raiders. Lyons' force swept through the city, destroying many hostiles and suffering only one casualty: Ishmael Ashur. Believing him to be dead, the Brotherhood gathered the surviving children into their ranks and continued toward Washington, D.C.

On their arrival, the wilderness outside the city was overrun by super mutants. Attacking head-on, they drove the mutants into the ruins of Washington, D.C. and earned the favor of the local population. Their investigation of the Pentagon uncovered a remarkable cache of technology, including the four-story-tall robot known as Liberty Prime. The discovery earned Owyn Lyons a promotion to elder and a change in his orders: instead of returning to the West Coast, they would establish a permanent presence in the area. They founded their base, the Citadel, in the remnants of the old Pentagon.

The Brotherhood's treatment of people in Pittsburgh and in Washington marked a characteristic trait of Elder Lyons' leadership. The Brotherhood's primary directive was to recover and preserve advanced technology. In many instances this directive was observed, even in the face of human suffering; however, Elder Lyon's detachment prioritized people's lives and well-being over machines, which is a far cry from the Brotherhood's traditional attitude. When the Elders in Lost Hills learned of these new priorities, they cut off all support to the chapter, though they still considered it as part of the Brotherhood. The chapter suffered a further setback when a number from within their ranks left in protest to form the Brotherhood Outcasts.

It was in this weakened and isolated state that it was possible for the Enclave, having relocated from New California as well, to re-establish a base of continual operations at Raven Rock, to make its move. They seized Project Purity, then set up outposts in Washington, D.C. and the surrounding wilderness. However, with the assistance of the Lone Wanderer, the Brotherhood ended the Enclave's presence in the known region; driving them first from Project Purity and then from their final holdout at Adams Air Force Base. The fate of the Enclave as a whole after these events remains a mystery.

Despite the Brotherhood's success with Project Purity and the war against the Enclave, the organization continued to struggle. Lyons would eventually pass away in 2278, leaving behind leadership to his daughter Sarah Lyons, who was then named elder in his place. However, Sarah was killed in combat shortly afterwards following her father's death. In the leadership crisis that followed, the Brotherhood repeatedly appointed and deposed one ineffectual leader after another until Arthur Maxson assumed leadership. In 2283, Arthur Maxson was appointed elder at age 16, the youngest in Brotherhood history, after displaying exceptional skill as a capable warrior and diplomat by defeating the super mutant leader Shepherd and brokering peace with the Brotherhood Outcasts, bringing them back into the fold.

By 2287, the East Coast Brotherhood had established contact with Lost Hills and Hidden Valley, and has actively received support from the West. During this time, they began to make plans to establish control not only over the Capital Wasteland, but the entire Eastern Seaboard. To complete this objective, they began constructing the Prydwen, using parts from the Enclave Mobile Crawler at Adams Air Force Base and a nuclear reactor from an old aircraft carrier. The development and construction process took a total of six years, two years to design the Prydwen and twice that to build. During this time, the Brotherhood sent three scout missions into the Commonwealth: first, a group volunteered to go into the Commonwealth, then two teams led by Paladin Brandis and Paladin Danse individually. The first scout team was overwhelmingly successful. They brought back crates full of pre-War technology and documents. The second team, however, was not so fortunate. They had bad luck from the beginning at their drop-off point in Malden. First being ambushed by Gunners straight off the Vertibird, which resulted in a large number of soldiers manually shorting out their power armor (and killing them in the process), the survivors made their way to an old National Guard training yard outpost, which was infested with feral ghouls and resulted in the death of another member of the team. The team then fell back to a pre-War military satellite base, but it was infested with super mutants, which resulted in the death of yet another member of the team. The only survivor was the commanding officer, Paladin Brandis, who made his way to a pre-War nuclear bunker, and took shelter there until either the Brotherhood or someone else found him.

The final recon team, Recon Squad Gladius, was to both establish a permanent Brotherhood presence in the Commonwealth to prelude the Prydwen ' s arrival, and investigate Recon Squad Artemis' disappearance. After completing these objectives, Danse was to give an "all clear" signal to the Prydwen to enter the Commonwealth, which after several technical delays with the Prydwen and an argument between Quinlan, Cade, Kells, and Maxson over Ingram's combat readiness (due to her using a power armor frame in place of her legs, which were blown off by a super mutant utilizing a Fat Man while she was field testing a suit of power armor for one of her fellow soldiers), with Cade giving his approval that she is in fact combat ready and his medical approval, Quinlan his technical approval, but Kells and Maxson denying her request, since they were worried that there could be a malfunction in the field, thus putting her fellow soldiers at risk, and couldn't risk it until they were absolutely sure it functioned properly and efficiently in a combat environment. Nevertheless, the Prydwen made its way to the Commonwealth in a spectacular fashion, making its way over the Commonwealth, dominating the skyline while under full Vertibird escort. Recon Squad Gladius made contact with the Prydwen, and the Brotherhood established a permanent foothold at the Boston Airport, and bolstered Gladius's position at Cambridge.

Major Outposts and Locations
The East Coast Brotherhood is a major military power boasting vast supplies, manpower, cutting-edge technology, and scientific research in all fields, enabling them to hold power and influence all across the Eastern Seaboard. They hold many strongholds and bases throughout the wasteland. They are:

GNR Radio Studio
In 2277, when Owyn Lyons was elder, the Brotherhood had a large presence at Galaxy News Radio, a news radio station in the middle of Washington D.C. It was tactically and strategically important as it was a defensible location in the middle of the ruins of D.C., as well as having a mutual relationship with the DJ of the studio, Three Dog. The status of this outpost as of 2287 is unknown.

Washington Memorial
Also in 2277, a small Brotherhood unit composed of ~5 soldiers was stationed here to defend the memorial, which had GNR's satellite on the top of it. Unfortunately, because of the chaos in this area (with slavers in the Lincoln Memorial, Talon Company, Super Mutants, and the Enclave in a three way battle to seize the Capitol building, and Super Mutants having a foothold in the National Archives and the numerous bunkers ironically established by the Brotherhood after making a push towards the Lincoln Memorial), casualties were high and the satellite dish often got knocked off, which resulted in the troops there simply using the same dish over and over again. After one such incident, the dish was irreparable, which resulted in a wild goose chase for another one.

Pennsylvania Avenue
The Brotherhood has a minor rest and resupply area near the nuked remains of the White House, making their home in an abandoned hotel, where they rarely sleep, due to the constant super mutant advances upon this location. The Enclave also has a drop off location east of this location, so the Brotherhood is almost always overwhelmed, leaving the Enclave and super mutants to battle it out. If the Enclave wins, they will sit around, eating and drinking the Brotherhood's rations and taking their weapons (if they happen to be stronger).

Arlington Library
The Brotherhood has a major presence at the Arlington Library (officially the Library of Congress), where, in 2277, Elder Lyons has Scribe Yearling searching for intact pre-War books to add to their collection. They are also trying to wipe out the raiders who have fortified themselves in the library and who have become an annoyance to the soldiers trying to salvage to library for books or anything of use.

Project Purity
After the near-end of the war with the Enclave, the Brotherhood established a foothold in the scientific complex known as Project Purity, which was underneath the Jefferson Memorial. This position, while easily defensible, was constantly under attack by either raider gangs or enraged mirelurks, leading to (again) heavy casualties from all sides. The Brotherhood employed Rivet City's Security Services to help them transport the water as well as protect the Project. It is unknown what has happened to the Project as of 2287, since Maxson moved the majority of the Brotherhood to the Commonwealth, leaving only a large contingency in his place.

Adams Air Force Base
After the destruction of the Enclave's Mobile Base Crawler, the Brotherhood set up a permanent basecamp at Adams, attempting to gather what they could from the wreckage to construct the Prydwen. Unfortunately, several setbacks delayed this effort, such as the death of both Owyn and Sarah Lyons, and the depositions of several Elders, until finally Arthur Maxson was appointed to elder, and directed all resources to the construction of the Prydwen. After 10 years, the huge airship was constructed, and they set upon the Commonwealth with haste.

The Citadel
The Citadel was once the bastion of the East Coast Brotherhood. Built in the ruins of the Pentagon, the courtyard was reserved for the training of initiates, who were trained by Paladin Gunny. From there, one could go to the Citadel Laboratory, where scribes tediously multitask between their duties to their order (The Sword, Shield, or Quill) and a special assignment by Head Scribe Rothchild; more specifically, Liberty Prime. Even a chapter as generous as Owyn's Brotherhood still understands that technology can still be dangerous if the common wastelander was to come across a giant robot designed to be a super weapon and could easily be reprogrammed (by someone with the right skills, of course) to see the Brotherhood as Chinese Communists. As such, the Brotherhood does not openly give tours of the Citadel, and security is probably more important than strike teams. Paladin Bael is in charge of security outside of the Citadel, while Knight Captain Colvin (via Sarah Lyons) is in charge of security on the inside. Of course, while security is a great concern, strike teams still need to be assembled and a strategy needs to formed. This is the function of the A-Ring. The Lyons Pride have their own council chambers (known as the Great Hall), where they either plan for future operations or direct field units. There are two small passageways connected to the Great Hall, used for storage, and both storing food and miscellaneous items. The northernmost room is known as the "Lyons Den," which serves as the rest and resupply reserved only for members of the Lyons Pride. The southernmost room is reserved for the Order of the Quill and all historical records pertaining to the East Coast Brotherhood, the Maxson bloodline, vaults in the Capital Wasteland, and the pre-War Pentagon.

Commonwealth
The East Coast Brotherhood holds numerous strongholds throughout the Commonwealth to serve as forward operating bases facilitating their operations against the Institute and other abominations in the Commonwealth.

The Prydwen
The main base of operations for the Brotherhood in the Commonwealth. The Prydwen serves as The Brotherhood's aerial aircraft carrier and contains all of the essential elements to make their operations possible. Including barracks, research and development facilities, medical bay, munitions stockpile, and more. Proctor Teagan commands the Order of the Sword from the stowage on the Prydwen, and he's also in charge of the supply depot in the airport, where he has put Knight-Sergeant Gavil in his liege as CO. Proctor Ingram commands the Order of the Shield from the power armor bay, whose job is to keep the Prydwen afloat as well as repair any damaged gear or equipment soldiers bring in. She has also been charged with repairing Liberty Prime to working condition so the Brotherhood can use it to destroy the Institute. Proctor Quinlan commands the Order of the Quill from his quarters on the main deck. His duty is to organize field scribe escorts as well as research and file technical documentation brought back from the field by the Brotherhood's soldiers.

Apart from the three Orders, Knight Captain Cade resides in the medical bay, treating wounded soldiers and assessing new recruits in order to see if they're combat ready. Cade is the one who refuses to clear Paladin Brandis for duty until the Sole Survivor completes either The Nuclear Option for the Brotherhood or completes Mass Fusion for the Institute while working for the Railroad. Lancer-Captain Kells commands the Brotherhood's air force as well as controlling the flight path of the Prydwen from the command deck.

Boston Airport
Used as a place to moor the Prydwen, the Boston airport serves many of the same functionalities as the Prydwen does. The Brotherhood uses the airport as a forward operating base for all of their operations in the Commonwealth. Supplies are stored here, as well as the remains of Liberty Prime, who the Brotherhood eventually rebuild to use against the Institute. The Brotherhood's best soldiers are stationed in front of where Prime is being built, where ranked soldiers up to sentinel primes can be encountered patrolling the walkway surrounding Prime. Behind Prime's building platform is the storage depot, where Knight-Sergeant Gavil (in liege of Proctor Teagan) stores all incoming rations appropriately, as well as supplying gear to field soldiers. Above that is a landing platform, where a general recreational area lies around it, where incoming and outgoing soldiers mingle before it's time for their next assignment. Benches, vending machines, and several food items lay about to allow the Brotherhood to relax with each other before heading out.

Cambridge Police Station
Cambridge Police Station is the main operating base of Recon Squad Gladius, and serves as a "port in the storm" for the Brotherhood as well as another more local forward operating base to facilitate their missions. Before the arrival of the Prydwen, a six man squad captured the station from feral ghouls (led by Paladin Danse), in order to function as their base of forward operations. As time passed, they lost two soldiers while on scouting patrol and another while under attack by feral ghouls. When the Prydwen arrived, however, the ghouls in Cambridge were merely a nuisance as synths began launching attacks on the police station. Now it functions as a rest and resupply before soldiers head back out into the chaos of the Commonwealth, with a Vertibird landing pad above and the rubble leading to it cleared. A power armor station lies beneath the station, with ample supplies to upgrade and repair any soldier's armor.

Society
The Brotherhood of Steel is a neo-knightly military order that rose from the ashes of the American military on the West Coast in the years following the devastation of 2077. The organization's tenets include the eradication of mutants, synths, and the veneration of technology. The Brotherhood has never been very keen on sharing their resources with their fellow wastelanders (whom they consider too ignorant and irresponsible to possess advanced technology). Despite their obsession with technology they will destroy technologies they deem too dangerous or uncontrollable, such as Institute synths.

The Brotherhood is generally beneficial to humanity, but in a more indirect way. They hunt down hostile mutants and synths, and they keep dangerous technologies out of careless or malevolent hands. Despite the obvious benefits their technology could bring to the wasteland they don't like to share their resources with outsiders, but would rather control the technology and use it themselves to help people in the wasteland. It is an established belief within the Brotherhood that the people of the wasteland are not responsible enough to possess or use advanced weapons technology. They believe that if everyone possessed these advanced weapons, the wasteland would be even more dangerous and chaos driven than it already is. However the Brotherhood is willing to trade some of their technologies with wasteland communities in return for supplies or even manpower, such as the arrangement with Rivet City security, and Diamond City but they always keep the more sensitive and dangerous technologies safe to themselves.

The Brotherhood's disdain for mutants and synths stems from their belief that such "abominations" are the direct result of reckless scientific experimentation, i.e, "technology run amok". They hold the irresponsible use of technology by pre-war civilizations responsible for the planet's destruction, and actively seek to prevent a second apocalypse from occurring by maintaining a monopoly on advanced weapons technology.

Recently, much like the chivalrous knights of old, the Brotherhood has been more interested in justice and safety for the obviously weaker and less fortunate around them to a certain extent, ghouls, and super mutants are not included as the Brotherhood believes them to be dangerous. Instead of keeping their secrecy, the Brotherhood has been far more assertive in the goings on of wasteland politics and life. They continue in their mission of preserving and developing technology. Their motives are often unclear, to those outside their ranks. Brotherhood members are not people to be trifled with. The East Coast contingent of the Brotherhood when it was first founded had "gone native" under the leadership of Elder Owyn Lyons. Lyons felt the Brotherhood had a responsibility to protect the people of the Capital Wasteland from the super mutant threat; a notion not entirely lost on Elder Maxson.

As of 2287, It is clear that the Brotherhood is an unrivaled power in the region, and draws most of its new recruits from the area. Based off of information from dialogue, terminals, and holotapes the Brotherhood appears to have evolved politically into an Ordensstaat (Order-State) akin to the old Order", and governs the Capital Wasteland directly as its own "country". Additionally, The Brotherhood now looks forward to the future, attempting to build more and improve technology, unlike their West Coast counterpart.

Military
The East Coast Brotherhood chain of command is divided into three clear levels.
 * Initiates are Brotherhood-born members and sponsored outsiders who are training to become knights, scribes or lancers.
 * Lancers are the backbone of the Brotherhoods newly formed airforce. Without them the Brotherhood would be unable to operate their vast fleets of VB-01 transport and VB-02 attack vertibirds.
 * Knights are fully fledged members who have served time in the Brotherhood. They are professional soldiers, and the main backbone of the Brotherhood's ground forces.
 * Paladins are the Brotherhood's elite, seasoned veterans that are often high ranking field commanders or used in elite strike teams.
 * Scribes are the brains to the Brotherhood's brawn. They are responsible for the development and research of all brotherhood technology, as well as the maintenance of advanced systems, weapons and armor and any other technical requirements.
 * Sentinel is a rare rank, only given to the Brotherhood's best and most distinguished soldiers. The last known sentinel was Sarah Lyons, daughter of Elder Owyn Lyons; she was the highest ranking field commander under Elder Lyons, and commanded the Lyon's Pride, a single squad of the chapter's best soldiers. It is unknown if the Pride still operates as of 2287. The Sole Survivor can achieve this rank through completion of A New Dawn. There are also two known BoS members at the Boston Airport that will eventually achieve the rank of Sentinel some time after the main quest is completed.

Sometime after 2277 the Brotherhood formed an air force for the operation and training of pilots for their captured Vertibirds. These pilots are known as lancers.

With all the Brotherhood's recent success including the defeat of the Enclave and subsequent acquisition of all Enclave technology and the reintegration of the Brotherhood Outcasts, the East Coast division of the Brotherhood is at the zenith of its power. They have access to Vertibirds, power armor, and energy weapons; as well as the ability to mass produce more of these according to Paladin Danse. They also possess a new and improved, rebuilt Liberty Prime. They also have the Prydwen, a colossal airship developed by the Brotherhood, which Paladin Danse claims houses enough troops and resources to "push a full scale offensive" and is capable of "mobilizing the whole division according to Arthur Maxson. Thanks to the Brotherhood maintaining their policy of open recruitment, their numbers on the east coast have vastly increased. Evidenced by the Brotherhood holding power and influence all across the eastern seaboard. Maxson refers to the Brotherhood as a division. Suggesting they could number from 10,000 to 20,000 strong.

In light of their recently acquired fleet of Vertibirds, the Brotherhood division under Elder Maxson now frequently conducts air assault operations within the Commonwealth, the foremost examples of which can be experienced in the missions Spoils of War and The Battle of Bunker Hill. Patrol and shock teams are frequently dropped into the Commonwealth to secure objectives deemed valuable to the Brotherhood or to eliminate hostile threats from an area.

Rank system
Exclusive to the current East Coast Brotherhood is a system of rank insignias among the knights and paladins. It has only been observed on their power armor so far but all the rank insignias appear to be based off a pentagon, which could be a reference to their base of operations the Citadel. The rank of initiate is an outline of a pentagon, then a full knight is a solid pentagon with chevrons added to it to denote knight-sergeants and knight-captains. A paladin's insignia is an elongated solid pentagon with a sword inside of it and a pair of wings flanking it. Sentinels and elders employ the same pentagon and wing motif but with a single diamond for sentinels and three diamonds for elders within the outline of a pentagon.

Special forces

 * Lyon's Pride - The "Pride", as it was known colloquially, was an elite unit of the east coast division of the Brotherhood of Steel under Elder Lyons. The Pride was led by the then-sentinel Sarah Lyons, daughter of the erstwhile Elder Owyn Lyons. Members of the Pride were hand picked, and represented the best that the Brotherhood had to offer. As of 2287 there is little to no information on the unit or its fate.

Relations with the outside
Originally under Elder Lyons rule, the East Coast Brotherhood was known to trade with outsiders, but as of 2277, there were many incidents which dissuaded the Brotherhood from such activities. The Brotherhood was also known to help patrol and defend settlements such as Megaton, until the super mutant threat escalated to the point that they were forced to withdraw from many key locations. In line with Elder Lyons' philosophy, Lyons' knights and paladins tried to protect any and all innocent wastelanders they encountered while out in the wasteland, and recruit them if possible. They were also known to hire mercenaries when needed, such as Reilly's Rangers. After the Battle of Project Purity, the Brotherhood began freely delivering Aqua Pura to settlements across the Capital Wasteland, working with Rivet City security and wasteland scavengers to organize the water caravans.

By 2287 the East Coast division of the Brotherhood has compromised between the former Elder Lyons' altruistic vision, and their traditional goals. They are relatively friendly towards human wastelanders and tolerate sentient ghouls, but have a generally hostile attitude towards super mutants, ferals and synths. The Brotherhood believes outsiders are too irresponsible and unrestrained to possess access to advanced technologies. They seek to control the dangerous technologies and would rather use them themselves to protect people rather than let the people themselves possess them. It is central to their beliefs that they must appropriate any dangerous technologies that they can control, and destroy the ones they cannot, such as the synths. By maintaining a monopoly on advanced technology, the Brotherhood hopes to protect the innocent and prevent a second apocalypse from occurring due to the irresponsible use of advanced technology.

Unlike the old West Coast Brotherhood, the East Coast division under Maxson has continued Lyon's practice of recruiting outsiders into the Brotherhood. While Lyons hastily welcomed outsiders into the ranks to bolster their forces, the Brotherhood under Maxson is more cautious, and recruits outsiders through a system of sponsorship. Under this system existing members of the Brotherhood can "sponsor" an outsider's entry into the ranks, making them an initiate. In this way the Brotherhood is able to balance its need for new recruits with their desire to ensure the loyalty of new members.

Technology
In 2277, the East Coast Brotherhood primarily used T-45d power armor; this armor was much more widely issued, being given to most front-line personnel, and not just select Paladins. They still used energy weapons, mostly the laser rifle and the laser pistol. However, due to the difficulty of finding, producing new parts, and maintaining the laser based weapons, and due to the fact that the Brotherhood no longer received supplies from the west coast, many paladins were forced to use traditional guns, notably the standard assault rifle and the Chinese assault rifle.

The Brotherhood formerly had access to Liberty Prime, a 40 foot tall communist-hating robot that packs enough firepower to decimate anything in its way. It was destroyed by an Enclave orbital missile strike, but members of the Brotherhood hold high hopes for its reconstruction. The Brotherhood has transported the disassembled parts of Liberty Prime to the Commonwealth, where they intend to rebuild it to use in the fight against the Institute.

After the war against the Enclave, the Brotherhood gained access to fleets of Vertibird gunships and stockpiles of laser weapons, plasma weapons, and power armor.

As of 2287, the Brotherhood of Steel has gain access to a huge arsenal of T-60 Power Armor (which replace the T-45 and T-51 Power Armor as the new standard issue power armour), a large number of energy weaponry (a great majority of the BoS members are armed with Laser Rifles and even Gatling Lasers) and even a vast supply of VB-01 and VB-02 Vertibirds, with the ability to manufacture even more according to Paladin Danse. They also possessed a heavily armoured airship, The Prydwen, which according to Paladin Danse, can carry enough troops and supplies to launch a major offensive. The airship also serves as their Mobile Command Center.

With the destruction of the Enclave, The Brotherhood Of Steel East Coast Division is currently the most powerful and technologically advanced faction in Post-war America, as they far surpass their West Coast counterparts in terms of numbers and technology (as the West Coast, for years, have struggled in their war against the NCR, and is force to go into hiding in underground bunkers).

They also possessed the most powerful combat robot ever seen in the waste, Liberty Prime. Although it was previously destroyed by Enclave Forces at Adams Air Force base, it was eventually rebuild into the new and improved Liberty Prime Mark II, which is far more powerful and destructive than its previous self. The faction that rivals or possess a threat to the Brotherhood are the mysterious Institute, the NCR (though the East Coast Brotherhood Division doesn't have to worry about them since they are in West Coast fighting the West Coast Brotherhood Division, while also facing huge losses), The Gunners (while still inferior to the BoS, they are still powerful in their own right, having access to limited Power Armour technology and laser/plasma weapons), The Minutemen (potentially) and The Railroad (potentially).

The War in the Commonwealth
The Brotherhood is a major player in the Commonwealth's fate, if the Sole Survivor decides to side with them. Before taking on the Institute, however, they must first establish their foothold around the Boston Airport, such as wiping out the super mutants at Fort Strong and, most importantly, getting Liberty Prime back online. This requires the help of Dr. Madison Li, a scientist who previously helped on the project ten years ago before heading to the Commonwealth to join the Institute. After infiltrating the Institute and recruiting Dr. Li, the Brotherhood solves the problems with attaching Prime's limbs, but unfortunately the giant robot requires a huge amount of nuclear energy, as well as Mark 28 nuclear bombs, which can only be found at the Mass Fusion headquarters in the middle of the ruins of Boston, and Sentinel site in the Glowing Sea, respectively.

After retrieving the nukes and the Beryllium agitator (and dealing with a traitor and the Railroad,) Prime is finally set to take on the Institute. Liberty Prime, assisted by the Brotherhood, blows through waves of synths while trekking through the ruins of Boston (stopping briefly to salute the memorial at Bunker Hill), and finally arrive at the ruins of CIT, where a huge Brotherhood contingent is fighting through the synths defending the ruins. While Prime scans for a weak spot to blow open an entrance to the underground facility of the Institute, the Brotherhood mops up any remaining synths sent to defend the outside of the facility. Prime finds a weak spot, and uses his lasers to blow a hole in the ground which opens to the old abandoned Robotics facility. The Sole Survivor takes point, aided by Elder Maxson (and Paladin Brandis, if they completed The Lost Patrol appropriately), as well as, depending on their level, several Legendary knight-sergeants, Legendary knight-captains, or Legendary paladins. Brandis has the potential of dying during this quest.

Maxson states his disappointment with the Old Robotics Center, saying that he expected much more from the Institute. As the squad fights through more synths and turrets, they enter the Bioscience area, where Maxson states that this is "exactly what he fears," in other words, science which is uncontrolled and unrestrained. They come to the atrium where several coursers and synths are waiting for them. After eliminating them, Proctor Ingram states over the intercom that they require access to the Advanced Systems area, but the lockdown engaged in the facility is preventing them from accessing it. The Sole Survivor goes to the Director's office, where Shaun is in the final stages of cancer. The Sole Survivor has the option of having one final conversation with him, where Shaun will condemn his parent for destroying everything he had built and where he had lived for his entire life. The Sole Survivor has the option of gloating over their victory or saying their goodbyes to their son. Shaun can also be persuaded to give the access code to shut down some very powerful synths guarding the door to the Advanced Systems area.

After overriding the lockdown (and optionally issuing the evacuation order, which will affect their reputation with the Minutemen and Preston Garvey in the future), the squad goes to the Advanced Systems area and, from there, the nuclear reactor area. The Brotherhood sets the blast charges on the reactor and, after some business with the Shaun synth, teleports to the top of the Mass Fusion building where the Sole Survivor presses the button that ends the Institute permanently. From here, the Sole Survivor is promoted to sentinel, and is free to carry out his own operations without reporting in to any superiors (though he is still held accountable for any actions taken that violate the Codex).

Alternatively, if the Sole Survivor decides to destroy the Institute with the Minutemen, his fellow knights and paladins state that they are angry they weren't invited to the "party," envious that the Minutemen have so much firepower, and surprised that the Minutemen actually had the strength to take on the Institute. Named characters, however, will react differently. Proctor Ingram will state that while it might not have been the Brotherhood way to use the Minutemen to destroy the Institute, it still got the job done, no matter what the cost, and approves of the Sole Survivor's actions. Proctor Quinlan says he approves of the "crater" in the middle of Boston, and how the Sole Survivor must be proud. He also states it was "ingenious" to use the Minutemen as "cannon fodder," thus minimizing casualties in the Brotherhood, and states his displeasure with his colleagues' "narrow-mindedness." Paladin Danse states that even though the Minutemen were used to get the job done, in the end, all that matters is that a new age in the Commonwealth is taking place, no matter who struck the killing blow to the Institute. The Sole Survivor, depending on choices made up to this point, will remain either a knight or a paladin, and will not recieve the promotion to sentinel, due to The Nuclear Option not being completed for the Brotherhood.

The Institute isn't the only problem the Brotherhood is having since landing in the Commonwealth. Proctor Quinlan requires technical documents found in pre-War ruins that might have information pertaining to important technology, weapon schematics, or military bunkers left behind in the war. Senior Scribe Neriah requires blood samples from heavily irradiated species such as feral ghouls, yao guai, and super mutants. Even after Danse is banished from the Brotherhood, Recon Squad Gladius still needs to complete their duties in Cambridge Police Station, such as cataloging tech or cleansing an area of radiation infected beings.

Appearances
The East Coast Brotherhood of Steel appears in Fallout 3, its add-on, Broken Steel, and Fallout 4. They are also mentioned in the other Fallout 3 add-ons, Operation: Anchorage, The Pitt and Mothership Zeta, and they are again mentioned in Fallout: New Vegas.

Behind the scenes
The East Coast Brotherhood of Steel have some similarities and differences with other Fallout games:
 * External recruitment is also present in Fallout Tactics, and for the "Texas Expedition" in Fallout: Brotherhood of Steel.
 * The Brotherhood Outcasts, renegades deserted from the newly established Brotherhood of Steel division are similar to the Circle of Steel in Van Buren.

Fallout 4
Hermandad del Acero de Yermo Capital Confraternita d'Acciaio della Zona Contaminata della Capitale Bractwo Stali Ruin Stolicy Brotherhood of Steel da Capital Wasteland Братство Стали (Fallout 3) Brotherhood of Steel (Costa Leste)