for the Criminally Insane is a mental hospital that appears in the fictional DC Universe. it is located near Gotham City, and is where many of Batman's foes are incarcerated. Probably the 'hospital's' most infamous patient is the Joker. The concept was created by Dennis O'Neil, and first appeared in Batman #258 (October 1974); much of its back-story was created by Len Wein during the 1980s.
Arkham Asylum does not have a good record, at least with regard to the high profile cases; escapes are frequent (on at least one occasion, an obsessive-compulsive multiple murderer was signed out of Arkham into the care of an incontinent alcoholic vagrant on the grounds that he "looked like a responsible citizen"), and those who are 'cured' and released tend to re-offend. (Furthermore, several staff members, including at least one director, have ended up as residents. See also Harley Quinn.)
In addition, prisoners with unusual medical conditions that the regular prisons cannot accommodate are housed here, like Mr. Freeze who requires a strongly refrigerated environment to stay alive.
In the world of the Batman stories, the Asylum is named after Elizabeth Arkham, founder Amadeus Arkham's mother. Its dark history began in the early 1900s when Arkham's mother, having suffered from mental illness most of her life, commits suicide. (Later revealed to have actually been mercy killed by her son to free her from her torment, an act Arkham's mind repressed.) Amadeus Arkham decided, then, as the sole heir to the Arkham estate, to remodel his family home in order to properly treat those with mental illness, so others might not go untreated and suffer as Arkham's mother had. Prior to the period of the hospital's remodeling Arkham treated patients at the State Psychiatric Hospital in Metropolis, where he and his wife, Constance, and child, Harriet, had been living for quite some time.
Upon telling his family of his plans, they move back to his family home to oversee the remodeling. While there, Arkham receives a call from the police notifying him Martin "Mad Dog" Hawkins -- a patient referred to Arkham by Metropolis Penitentiary while at State Psychiatric Hospital -- had escaped from prison, and sought his considered opinion on his state of mind.
On April 1st, 1921, Arkham returned to his home to find his front door wide open. Inside, he discovered the raped and indescribably mutilated bodies of his wife and daughter in an upstairs room, Hawkins having carved his nickname on Harriet's body.
In spite of everything, the Elisabeth Arkham Asylum for the Criminally Insane officially opened in November of 1921. One of its first patients was Martin Hawkins, and Arkham is praised for his courage and compassion in dealing with his family's murderer. On April 1st, 1922, after treating Hawkins for six months, Arkham straps him to the electroshock couch and purposely electrocutes Hawkins. The death is treated as an accident, but contributes to the continued loss of Arkham's mental stability, which Arkham begins to believe is his birthright.
In reality, Arkham Asylum is named in honour of the fictional city of Arkham, Massachusetts, one of the settings of H. P. Lovecraft's horror stories. In fact, when the asylum first appeared, it was actually in the city of Arkham; its Gotham location, and the consequent alternative explanation of the name, were later retcons. H.P. Lovecraft's Arkham Sanitarium may have been inspired by the Danvers State Insane Asylum (aka the Danvers State Hospital) in Danvers, Massachusetts.
This first appearance was in 1974, in Batman #258 by Dennis O'Neil. In this story, it was named as "Arkham Hospital" (although it was already clear what kind of hospital it was); "Arkham Asylum" first appeared in another O'Neil story the following year, but it was not until 1979 that "Arkham Asylum" completely replaced "Arkham Hospital" (and the occasional "Arkham Sanatarium") as the institution's name. By 1979, too, the move to have the asylum closer to Gotham had begun; that was completed in 1980, when Batman #326 by Len Wein described the Asylum's location "deep in the suburbs of Gotham City". (Perhaps for this reason Batman #326 is listed in some histories as the first appearance of Arkham Asylum.) It was also Wein who, in 1985's Who's Who #1, created the current back-story in which Arkham Asylum was founded in Gotham in the 1920s by Amadeus Arkham.
Arkham Asylum has been demolished or destroyed several times in its history, notably during the events of Batman: The Last Arkham (see below). It was also seriously damaged at the beginning of the Knightfall storyline, when Bane used stolen munitions to blow up the facility and release all the inmates. After these events, the asylum was relocated to a large mansion known as "mercy house", where it remains to this day. At the beginning of the No Man's Land storyline, the asylum was closed down and all its inmates set free. With the sole exception of the Riddler, the inmates elected to remain in the cut-off Gotham City.
Originally, Arkham Asylum was used only to house genuinely insane characters - the Joker and Two-Face were inmates from its very first appearance - but over the course of the 1980s a trend was established of having the majority of Batman's supervillain opponents end up at Arkham, whether or not they were actually insane. Nearly all of Batman's villains have spent some time in Arkham.
Even a former Arkham employee is now an inmate; psychiatrist Dr. Harleen Quinzel went insane and turned to crime, as the loony Harley Quinn, after the Joker, then her patient, seduced her and enlisted her as his sidekick.
Other 'DC Universe' publications that feature Arkham Asylum and its inmates include Alan Moore's Swamp Thing (wherein Jason Woodrue (The Floronic Man) is detained) and The Sandman by Neil Gaiman, wherein John Dee (Doctor Destiny) escapes to wreak havoc on both the 'real' and 'dream' worlds.