Jeremiah Arkham was the head of Arkham Asylum, an institution for the criminally insane. He debuted in 1992. He became an insane supervillain taking the name of Black Mask.
Batman: The Last Arkham
In Batman: The Last Arkham, Jeremiah is portrayed as the somewhat sadistic administrator of Arkham Asylum who has delusions that the criminals he houses could one day be housed in society. The Asylum had come into Jeremiah's possession after his uncle Amadeus Arkham died after going mad. Jeremiah proceeded to demolish the asylum before rebuilding it with state of the art systems to keep Arkham's criminals, such as The Joker and Two-Face contained.
Jeremiah's background was touched upon briefly. Although not much is known about his prior history, the issue states that when he was a teenager he walked into a corner store being held up at gun point by an escaped inmate of the nearby Arkham Asylum, which was coincidentally run by his uncle. The gunman had already killed the storeowners, but when he went to shoot him, Jeremiah seemed to know all about the gunman's past and talked the gunman out of shooting him. The gunman then proceeded to commit suicide and Jeremiah knew he would be destined to succeed his uncle as the head of Arkham Asylum.
Soon after the new Arkham is built, Batman stumbles across a series of murders resembling Zsasz's motive. Zsasz had been an inmate at Arkham Asylum for a long period, but the similarity was too much to ignore, so Batman fakes insanity to get into the asylum to investigate. However, Jeremiah is unknowing of this plot and takes Batman's insanity as genuine. Zsasz had actually been the murderer and had been getting out of Arkham by a series of underground tunnels put in place by the contractor on the asylum's revamp. Zsasz, upon hearing of Batman's arrival, predicts it's a set-up and begins to plant seeds of doubt and hatred towards Batman in Jeremiah Arkham's mind. In addition to this, Jeremiah blames Batman for stopping his inmate's rehabilitation. The situation erupts when Jeremiah locks Batman in a room and sets the inmates of Arkham on him, including Amygdala, The Riddler, and others.
Batman questions whether Jeremiah is himself mad. Jeremiah denies it, but in the closing scene of the comic, he asks himself whether he will end up like his insane uncle and whether he is indeed mad as Batman suggested.
Jeremiah Arkham returned once again during Knightfall. His role began when he was held at gunpoint by The Joker after Arkham Asylum is attacked by Bane in order to free the asylum's inmates. The Joker attempts to scare Jeremiah into madness and Jeremiah is only saved when Batman frees him from the Joker's trap.
No Man's Land
He opened the Asylum gates, believing it was better for his patients to be at large in a mostly abandoned city than trapped in the Asylum with limited supplies.
Batman: Battle for the Cowl
He envisions a plan to rebuild Arkham Asylum, after it was destroyed by himself posing as the new Black Mask following his capture and defeat by the new Batman.
Jeremiah returns to Arkham Asylum after it has been destroyed. On his return he finds that some of the patients are still there, including his three 'special' subjects that no-one knows about. They are No-Face, Mirror-Man and the Hamburger Lady . Once back in his office, Jeremiah finds his office a mess, spooky graffiti on the mirror and the journal of Amadeus Arkham on his desk, though he thought he had burnt it. He finds his uncle's original plans for the Asylum and decides it is an omen and thus starts to rebuild according to the plans.
The Asylum re-opens with the disgruntled blessing of the Gotham Shield Committee, consisting of Bruce Wayne, D.A. Kate Spencer and Commissioner Gordon. He is also joined by Aaron Cash (head of Arkham security) and the new assistant director, Alyce Sinner. As the Asylum gets more complete more accidents happen. The Raggedy Man is set loose, Clayface gets sick, Mr Freeze's room heats up and Killer Croc's tank filtration breaks. As these events pass, Jeremiah becomes more stressed and unhinged, spending more time with his special patients. Meanwhile, it is revealed that Alyce is having sexual relations with Black Mask. Once back at the asylum, she uses the computers to project the voice of Amadeus to the inmates and make them riot. Batman then intervenes and gets all the inmates back to their cells. Raggedy Man is found dead and Jeremiah is starting to fall apart. This is all part of the plan of Black Mask. Alyce reports back to him, apparently doing this for the money, and claims she also wants the asylum. Jeremiah works out with Batman's help that Alyce is behind it all and she is committed. When he goes to talk to his special patients for some mental release he is confronted by a scary Jester figure (reminiscent of Joker).
It is at this point he loses it. He is found by Batman and locked up with the other inmates in Arkham and Alyce is freed and made Director of the asylum. In the end it turns out that his special patients were all a delusion and he also suffers with no recollection of when he is the Black Mask.
He discovers this when Batman takes him to see the special three and after some intense moments Jeremiah attacks and kills them. He then completely breaks down and breaks the Jester staff, which releases a gas. He is then put in intensive care, where Zsasz, who had threatened him earlier, comes to kill him and mark the scar inside his eyelid. But when Batman gets there, Jeremiah has tied up Zsasz and cut off his lower eyelid. This results in him being locked up and put in the care of Alyce. He confesses to her that he knows he is Black Mask and Zsasz is proof. She then kisses him and they are seen hugging.
Later, still locked up, he had forgetten his love about Alyce, although they remained allies. He and Fright began to be lovers, which is because of their different intellect in different subjects.
In Other Media
Lego Batman: The Videogame
Dr. Jeremiah Arkham is an ally of Batman who appears in the Nintendo DS version of LEGO Batman: The Videogame. He was mentioned in the Data section on console versions but only appeared and was playable on the DS.