NOTE: This article is about the Arkham Knight introduced in Detective Comics #1000. For the version seen in the "Batman Arkham" series, see Arkham Knight (Arkhamverse).
The people of Gotham City deserve better than a Dark Knight. They will experience the hand of a fair and true servant at work. And they will bare witness to the Arkham Knight finally delivering justice to the Batman.
~ Arkham Knight
Astrid Arkham, also better known as the Arkham Knight, is a character from DC Comics and an adversary of Batman. She is the daughter of Jeremiah Arkham who believes Batman to be a threat to Gotham City.
Astrid was born in Arkham Asylum, and her mother was killed by an unnamed prisoner with a Batarang during a riot. She raised within the asylum where her father could keep her close and walled off from the rest of Gotham. However, Astrid would always find ways to sneak into areas she was not suppose to go and interact with asylum inmates. One day, Astrid witnessed Batman fighting criminals on asylum grounds and she eventually came to believe Batman was a villain she needed to oppose as a way of dealing with her fear of him.
As Astrid got older, she became more firm in her belief of Batman's villainy (something further enforced by the inmates) before learning that a Batarang was used to kill her mother, which pushed her enough to become the Arkham Knight. She proceeded to work hard for months to prepare for her assault against Batman, and plotted to bring about an event she called "the eclipse" with the help of her followers. The Arkham Knight begins by poisoning Gotham City's bat population, which kills thousands of bats and seems to almost cost the the life She-Bat, before activating a powerful device that creates an miniature artificial sun in the night sky.
Batman is then attacked at Gotham Zoo by an organisation of the Arkham Knight's followers called "Knights of the Sun". During the assault, Batman realizes the knights all wield medieval weapons that can pierce through his armor and wear outfits that deflect his Batarangs. He attempts to draw the knights away from civilians nearby using a smokescreen, but the Arkham Knight emerges to knock the smoking projectile back at him before pinning Batman to the ground. With her foe weakened, the Arkham Knight raises her sword to execute him, but is suddenly shot with a barrage of bullets fired by nearby police.
She survives the shooting due to her suits armor before the situation quickly escalates into a fight between her forces and the GCPD. The Arkham Knight manages to bring the conflict to a standstill after throwing herself in front of stray bullets to save a female officer's life, and after a brief standoff between the opposing sides Batman decides to cease fighting with the knowledge that neither he or the Arkham Knight want any citizens being harmed in the crossfire. Astrid agrees with Batman and uses a flashbang to make her escape.
Sometime later, the Knights of the Sun take a sub to the bottom of Aparo Bay in search for energy fragments that their "Day Bomb" disbursed across the city. However, they soon encounter Robin (Damian Wayne) also gathering fragments and attempt to subdue him. The Boy Wonder manages to fight off his aggressors until the Arkham Knight stuns him from behind and renders him unconscious. The knights then return to their hideout beneath Arkham Asylum, where they imprison Robin in a dungeon after refusing an offer to join their crusade. Damian manages to escape his cell by crawling through a long ventilation shaft until he finally finds an access hatch to escape. However, he opens the hatch to find himself face-to-face with the Arkham Knight again, who decides to try harder in convincing the boy as she reveals to him her true identity.
Astrid tells her follows in the room to lower their weapons, but Robin recognizes them as criminals he had previously put away and quickly aggravates them into shooting him with an arrow. The Arkham Knight furiously orders them to stand down, cutting off a follower's hand with her sword. Robin then grabs the bow which the severed hand was holding and uses it with the arrow that hit him. Damian draws the bow and dares his foes to make the next move but Astrid allows him to walk free and tells him to think about her previous offer to join their cause.
Afterwards the Arkham Knight began to furiously reprimand two followers who disobeyed her orders, telling them that she needs absolute loyalty from all her Knights of the Sun to make "the eclipse" happen. She releases Doctor Phosphorus from his cell and has him punish them by burning their backs. While Batman and Robin search for more answers, The Knights of the Sun head to the Gotham Observatory where Astrid plans to initiate the eclipse by using the buildings telescope to magnify a more powerful Day Bomb that will blind the city's citizens. She believes this will give her the chance to make Gotham accept the Arkham Knight as the city's new protector if she assists in its recovery.
Soon the dynamic duo approach Astrid's location and she orders her knights to launch a barrage of arrows while her supervillain acquaintance Anton Arcane summons his Un-Men to protect the observatory. Batman cuts through the creatures and battles Dr. Phosphorus as Robin stops Arcane from calling forth more Un-Men. After both villains are down, The heroes enter the observatory but the Arkham Knight activates her Sun Bomb which covers Gotham in a beam of light. Batman acts fast to prevent the device from causing permanent blindness. He attacks the Arkham Knight, and during the fight they both tumble into the telescopes lens, shattering it. With the lens broken, the light engulfing the city recedes and the Arkham Knight is arrested for her crimes. However Astrid manages to escape her incarceration weeks later while being moved to Blackgate Prison.
The Arkham Knight has a strong dislike for Batman, who she believes is contributing to Gotham's problems instead of fixing them. She seems to know a lot about the gear Batman uses, since she provided her Knights of the Sun with equipment that can counteract Batman's technology and projectiles. Despite her vendetta, the Arkham Knight appears to care for the safety of Gotham's citizens. However, she is apparently willing to use harmful, life-altering measures against them to try and convince the city to accept her as their vigilante protector rather than Batman.