Amadeus Arkham originally founded the Elizabeth Arkham Asylum for the Criminally Insane in the memory of his mother, whom he euthanized as treatment for her dementia. That historic facility was built on the grounds of Amadeus Arkham's historic mansion on the outskirts of Gotham City on the secluded Arkham Island.
Amadeus personally treated its first inmate, Martin "Mad Dog" Hawkins, who had killed his wife and daughter. After being claimed sane enough to walk free, Martin was due to be released, until he took a fountain pen from Amadeus' desk and murdered his secretary. At some point, Martin went to the Botanical Gardens on the island and desecrated the statue that was raised by Amadeus in memory of his family. Those many tragedies pushed Amadeus over the edge, and, during a session of electroshock therapy, he murdered Martin. Amadeus was later ruled insane and was incarcerated in his own asylum, where he later died. Amadeus' gravestone was located outside next to the Botanical Gardens.
Over the years, the asylum gradually developed with new facilities such as the Penitentiary being established. However, it was eventually closed down soon before the Arkham Origins Incident - possibly because more criminals were instead sent to Blackgate Prison which later proved to be unfit for housing the criminally insane. Once reopened, the facility was voted as the number one psychiatric and rehabilitation facility in the state. However, the infamous reputation remained as more high profile criminals frequently managed to escape its walls.
That developed to become a premium 500 bed psychiatric facility holding a range of individuals who were criminally insane. For the past two years prior to the Arkham Asylum Incident, the facility offered internships to University Students to help them gain valuable experience for a career. Arkham Asylum's own website, ArkhamCare, was the online public face of the facility that was designed to inform potential patients and family members about the institution.
During that time, Arkham Asylum had developed from the Arkham Mansion and the Botantical Gardens into the Elizabeth Arkham Asylum for the Criminally Insane thanks to Amadeus Arkham. The institution gradually developed, but was eventually abandoned, possibly because more of Gotham's criminals were being sent to Blackgate Prison instead of Arkham Asylum.
Arkham Origins Incident
Arkham Asylum could be seen in the distance from Gotham's mainland, but during that incident, the asylum was not operational, so the criminally insane individuals were mostly treated within other institutions, such as Blackgate Prison. However, Quincy Sharp did speak about his intentions to renovate and reopen the asylum in the following months as it would function as a highly appropriate facility to house and treat severe mental illnesses.
Cold, Cold Heart Incident
Arkham Origins Blackgate Incident
At around the same time of this incident, Arkham Asylum had been fully renovated and was in a fit condition to house the criminally insane, thanks to the efforts of Sharp who became the new Warden. Facilities such as the Intensive Treatment Center and the Medical Facility were drastically developed so the asylum could function as a hospital, while the improved Penitentiary ensured that the growing number of 'super criminals' remained safely incarcerated.
Fully Renovated Asylum
Very soon, after the Arkham Origins Blackgate Incident, patients such as the Joker were transferred to Arkham Asylum, so that they could receive the optimal level of treatment for psychological illnesses. Additionally, staff such as Dr. Young and Aaron Cash were employed there.
Over the years, Arkham Asylum further improved to become a leading institution for psychiatric research with new facilities such as laboratories being added, and with new cells such as Extreme Isolation being added to house a wider variety of the criminally insane patients.
Assault on Arkham Incident
The Riddler was incarcerated by Batman in the facility, after he attempted to interrogate him about a dirty bomb the Joker stole. Because of this, the Suicide Squad (by that point composed of veterans Deadshot, Harley Quinn, and Captain Boomerang as well as newcomers Black Spider, King Shark, and Killer Frost) were dispatched by Amanda Waller to infiltrate the asylum to find classified data the Riddler had allegedly stolen from their mainframes. Although they ultimately managed to infiltrate the asylum with help from the Penguin, they ran into a few snags due to an unexpected encounter with the Joker, as well as a gas explosion causing a yellow alert, the latter of which forced them to swap security footage videos in a failed attempt at delaying Batman's interference. They ultimately went against their mission after they learned not only that the real mission was to assassinate the Riddler, but also the reason why due to his having knowledge on how to diffuse the nanite bombs (due to Riddler having formerly been a Suicide Squad member himself), which they promptly used to disable their own bombs, although at the cost of the lives of both Black Spider (due to Batman swapping places with him) and King Shark (due to his tough skin making the electro-shock method useless). Joker, who escaped due to exploiting a weakened part of the security defenses via Harley Quinn's earlier attempt at revenge towards him, also proceeded upon recovering the dirty bomb via Harley's mallet, engineer a jailbreak of the various inmates as insurance that Batman cannot stop his plan in time. Harley ultimately defected back to the Joker, while Killer Frost was thrown while inside of a police car into a mountain by Bane, Captain Boomerang was left at the Asylum, while Deadshot was the only one to actually escape besides Joker and Harley Quinn.
A Matter of Family Incident
Arkham Asylum could be seen relatively close to the Seagate Amusement Park that Robin and Batgirl were on while they were trying to save Commissioner Gordon from the Joker and Harley Quinn. The psychiatric institution remained fully operation during that time with a number of insane individuals as well as insane super criminals who were incarcerated there away from the Gotham City mainland.
Arkham Asylum Incident
Following a number of the patients' breakout attempts over the years, Warden Sharp had the asylum's security and facilities make a great improvement, and ensured that the inmates did not escape - something that was quickly noticed by the Joker. For example, new electrical barriers, suicide collars, weapon detectors, and CCTV's were introduced to ensure that the patients' behavior could be more easily controlled.
Despite that, a mysterious fire at Blackgate Prison resulted in all of the Blackgate Prisoners being transferred to Arkham Asylum, which put a great strain on the facilities. That proved to be problematic as the staff could not closely monitor so many prisoners, which resulted in Harley Quinn being able to escape and sneak to the Security Control Room. During that incident, the asylum was gradually desecrated by the patients, and Poison Ivy's Plants were mutated by Titan which damaged a large section of the asylum.
Arkham City Incident
Using the Arkham Asylum Incident in his favor, Sharp became Mayor of Gotham City and proposed the creation of Arkham City: a sectioned off quadrant of Gotham City that was devoted to the incarceration of Arkham patients and convicts alike. Once Arkham City had been approved, Mayor Sharp ordered that Arkham Island be sold. A number of prominent companies bid for the land, but it ultimately went to a previously unknown security company that was named TYGER.
Within weeks of the sale, TYGER was also awarded the contract to police Arkham City and instantly began using Arkham Island to launch its fleet of helicopter gunships to police the new prison facility. As seen from Arkham City, the damage of Poison Ivy's vines had not been removed by that time.
Arkham Unhinged Incident/Arkham Knight Comics Incident
Around the time of the Joker's death, Joker posthumously revealed that the walls of Arkham City were rigged to blow, and he hinted that the answer to defusing them would be at the Intensive Treatment Center cell that he was once incarcerated in after an incident on the Fourth of July. That section of Arkham Asylum ended up being destroyed by a bomb rigged inside the cell, which nearly resulted in Batman's death, though he escaped. The Arkham Knight also went over there, deduced that the cell was rigged, and did not want Batman be killed before he had his shot at him, although after he found the Joker's "Die-ary", he mentioned that the night wasn't a total loss.
Arkham Knight Incident
With Arkham Asylum abandoned by TYGER, Scarecrow took over the Arkham Mansion as his secret base, arranged a meeting with the other super-criminals, and devised a plan to 'break' Batman. Once again, the asylum could be seen from the Gotham City mainland, and was in the exact same condition as the Arkham Asylum Incident.
Scarecrow kidnapped Robin and Commissioner Gordon, took them to the asylum, and forced Batman to turn himself in to save them. Scarecrow took Batman to Arkham Asylum where he had him rolled in on a prisoner gurney, much like the way that Batman and the guards brought in the Joker in Arkham Asylum two years earlier. Scarecrow had Batman transported in a truck to the Arkham Mansion, which was still overrun with Ivy's plants. It was here that Scarecrow revealed Batman's secret identity as Bruce Wayne to the world. Jason Todd, who tracked Scarecrow's truck, arrived in time to stop him from killing a restrained Batman and rescued his mentor, who managed to inject Scarecrow with his own Fear Toxin, and effectively ended the Master of Fear's reign of terror over Gotham City.
After Arkham Knight Incident
After the Arkham Knight Incident, the institution was very likely to have been renovated once again to house the criminally insane with a new warden and more staff. The number of patients would be managed in order to avoid another large scale breakout attempt.
- Being the only location that visitors could access, this location was designed for relatives to be able to safely visit patients under close surveillance by the asylum's security. The Visitor's Center included a reception desk for visitors to sign in, as well as multiple booths behind glass in which the patients sat behind when they talked to their relatives.
- A large facility located in the center of Arkham Island, the Intensive Treatment Center held a number of the more extreme personalities and was designed to provide care for highly severe psychological and physical illnesses. This unit contained a number of holding cells, many offices for the Arkham Staff along the corridors, the Extreme Isolation cells, a wide range of medical equipment, the island's main lobby, and access to the sewer where Killer Croc was housed. This was one of the island's most highly secure buildings where patients are first admitted for initial assessments, so it had up-to-date security systems to properly house inmates.
- One of the newer additions to the Arkham Asylum, the Medical Facility was one of the primary locations for the criminally insane inmates of the institution to receive physical treatment, alongside the Intensive Treatment Unit. This building had a sanatorium with an X-Ray Room, a Patient Observation Room and a Surgery Room leading off from it as well as an elevator which lead to the lower floor where Dr. Harleen Quinzel's abandoned office could be found. The entire interior appeared modern yet decayed, possibly due to patients mistreating the facility.
- The primary location for incarceration, the Penitentiary contained a great number of different cells to house the asylum's extreme variety of inmates. In the center, cells for the Arkham Lunatics were located which lead into various wings. The Green Mile was the primary housing location of Poison Ivy which was located along the corridor to the Security Control Room - the main room for where the whole asylum's security measures were controlled. The unit also contained the Extreme Incarceration cells where a number of Gotham's super-criminals such as Mr. Freeze were housed.
The Arkham Mansion
- The oldest building on the island, the Arkham Mansion was originally the home of the Arkham Family until Amadeus Arkham decided to turn the island into the Elizabeth Arkham Asylum for the Criminally Insane. This was constructed with a Gothic, Victorian architecture with a large clock tower located on top of the mansion. Inside, the Arkham Mansion contained long corridors that lead to various rooms such as the Library, Dr. Young's Office, the Arkham Records Room, the Warden's Office, and Amadeus Arkham's Cell.
- One of the oldest structures on the island, the Botanical Gardens were located next to the Arkham Mansion. These gardens functioned as a place of leisure for inmates to visit in their free time, evident by Humpty Dumpty's deconstructed toys located on a bench in there. These gardens also offered a location for doctors to study biological research, such as in the Titan Production Facility. The Botanical Gardens were filled with an assortment of plants as well as rooms such as the Elizabeth Arkham Glasshouse that was dedicated to Amadeus' mother.
- Located deep beneath the surface of Arkham Asylum, the sewer systems were accessible through the Intensive Treatment Center elevator where Killer Croc was incarcerated or through an abandoned door leading from Arkham North. This contained tunnels of sewers, old brick corridors, a Pump Control Room, as well as a hidden Batcave that was designed for any breakout attempts. The system was poorly maintained. However, it was occasionally visited by the Arkham Staff to assess, incarcerate, or treat Killer Croc.
- Extreme Isolation is an area of Arkham that is located in the Intensive Treatment Center and reserved for only the most dangerous of inmates. An almost inescapable prison, the only way in and out of the area is via a high-security, metal transfer box. The entrance is also guarded by six heavily armed and armored security guards at all times. Notably this was the only area that Batman was not able to infiltrate and was apparently not a concern of the Dark Knight as he never mentioned it again after its inital debut suggesting that it is the most secure area on the island. The only known inmate from the Extreme Isolation seen was the Titan Henchman whom had previously been banished there by Dr. Penelope Young and then released by the Joker. Rumors persist that this may have been where the Joker and the Scarecrow were kept when imprisoned.
- Warden Quincy Sharp
- Dr. Penelope Young
- Dr. Sarah Cassidy
- Dr Stephen Kellerman
- Kevin Liew
- Mike (Orderly)
- Robert Stirling
- Dr. Adrian Chen
- Dr. Gretchen Whistler
- Ian Kennedy
- Dr Thomas Elliot
- Dr. Harleen Frances Quinzel (Formerly)
- Professor Hugo Strange
- Dr. Jonathan Crane (Formerly)
- Aaron Cash
- Frank Boles (Formerly)
- Thomas Armbruster
- Henry Smith
- Eddie Burlow
- Maria Andrade
- Louie Green
- Zach Franklin
- William North
- Mike (Guard)
The following was a list of inmates in Arkham Asylum, past and present:
- Edward Nigma/Riddler
- Waylon Jones/Killer Croc
- Victor Zsasz
- Maxie Zeus
- Razor (shipped in from Blackgate)
- Dr. Harleen Frances Quinzel/Harley Quinn
- Dr. Pamela Lillian Isley/Poison Ivy
- Basil Karlo/Clayface
- Harvey Dent/Two-Face
- Julian Day/Calendar Man
- Dr. Victor Fries/Mr. Freeze
- Arkham Lunatics
- Dr. Jonathan Crane/Scarecrow
- Oswald Cobblepot/Penguin (shipped in from Blackgate)
- Selina Kyle/Catwoman (shipped in from Blackgate)
- Arnold Wesker/Ventriloquist
- Warren White/Great White Shark
- Humphry Dumpler/Humpty Dumpty
- Jervis Tetch/Mad Hatter
- Drury Walker/Killer Moth (shipped in from Blackgate)
- Venom Henchman (shipped in from Blackgate)
- The Blackgate Prisoners
- Otis Flannegan/Ratcatcher
- Deever and Dumfree Tweed/Tweedledum and Tweedledee
- Jason Todd (secretly kept prisoner there by the Joker for an entire year)
- Garfield Lynns/Firefly
- A while before the events of Batman: Arkham Asylum, Jason Todd was kidnapped by the Joker and tortured for over a year in an abandoned wing at Arkham Asylum while the institute was still open. The whereabouts of the torturing were unknown, although it was possible that the torturing took place in Amadeus Arkham's former cell at the Arkham Mansion, which would explain the presence of Amadeus' carved symbols and writings that could be seen on the floor upon close and careful inspection.
- The chimneys on the Intensive Treatment Center, though present during Batman: Arkham Asylum, could not be seen during Batman: Arkham City or Batman: Arkham Origins. The reason for that was unknown, though it may have just been a continuity error.