A.J. Quartermaine (Sean Kanan)

'''Alan "A.J." Quartermaine Jr.' was a character on General Hospital''. The son of the wealthy Dr. Alan and Dr. Monica Quartermaine, A.J.'s storylines centered on his battle with alcoholism, his family's preference for his brother, Jason Morgan, and his failed attempts to regain custody of his son, Michael. The character was played by a variety of child actors from 1979 - 1989, and then as an adult from 1991 until the character was killed off in 2005. Notable actors who played  the role included Sean Kanan (1993-1997) and Billy Warlock (1997-2003, 2005).

Childhood
A.J.'s mother, Monica, initially thinks that A.J's father is her lover, Dr. Rick Webber. But after A.J.'s birth, an unusual birthmark and a rare blood type help prove that he is a Quartermaine. During childhood, A.J. is sent to a boarding school in Switzerland with younger paternal half-brother Jason. Monica, along with most of the family, favors Jason over A.J.

College years
When the boys return to Port Charles as teenagers, A.J. battles a drinking problem that grows worse over the next years. He starts a loan shark operation in college and has an affair with Nancy Eckert, the ex-wife of Spencer cousin Bill Eckert. He pays someone to have her beat up to keep quiet about his misdeeds. During his college year, he is arrested twice for drunken driving, and his brother Jason is injured while trying to prevent A.J. from driving drunk. Jason falls into a coma, and when he recovers, no longer remembers anyone. He becomes estranged from every Quartermaine except younger adopted sister Emily Bowen-Quartermaine, cousin Ned Ashton, and grandmother Lila Quartermaine. Jason goes to work for mobster Sonny Corinthos as a hitman. The Quartermaines blame A.J. for the loss of Jason.

During college, A.J. also develops a relationship with Nikki, a distant relative through Dawn Winthrop, a daughter Monica gave up for adoption before her marriage. Nikki is not related to A.J. by blood, but the Quartermaines do not like this close connection. A.J.'s father Alan pays off Nikki to leave town.

Michael and Carly
A.J. has a drunken one-night stand with Carly Corinthos, who is involved with Dr. Tony Jones. When Carly learns she is pregnant, she is unsure which man is the father, but goes to great lengths to keep A.J. from becoming suspicious. A.J. has stopped drinking and is attempting to straighten out his life, but Carly drugs him, hefts him into a laundry cart, dumps him in a back alley behind a bar and pours alcohol all over him. She wants him to think he's been drinking so he will go to a rehabilitation facility out of state, as she does not want him around when the baby is born. Her efforts backfire, and A.J. becomes suspicious. He demands a DNA test and tells Carly he wants custody of the baby if it's his. Carly persuades Jason, another of her ex-lovers, to assume paternity of the baby. When Michael is born, A.J. misunderstands a doctor's explanation about the baby's blood type and mistakenly believes Michael could not be his. A few years later, Jason's girlfriend Robin Scorpio tells A.J. that he is, in fact, the father. A custody battle between Jason and A.J. follows. A.J. marries Carly and takes Michael to live with him, but finds it difficult to connect with the toddler, who is closely bonded to Jason. Ultimately, Carly has an affair with Sonny Corinthos, becomes pregnant by him, and Jason leaves town. A.J. initially offers to raise Sonny's child as his own, but the marriage breaks up. Carly miscarries after she falls down a flight of stairs during a fight with A.J. She marries Sonny, who blackmails A.J. with his knowledge that A.J. hired an arsonist to burn down Sonny's warehouse, also in an attempt to regain custody of Michael. Sonny has his henchmen hang A.J. from a meathook, and threatens to kill him unless A.J. signs away his rights.

Marriage to Courtney
A few years later, A.J. marries Sonny's half-sister Courtney Matthews, thinking he can use her to gain revenge against Sonny and perhaps regain custody of Michael. A.J. falls in love with Courtney and is happy for a time. When faced with the choice of choosing Courtney or the Quartermaines, he chooses his wife, and is cut off financially from the family. Faced with endless ridicule at his new job, he gets drunk one night and drives into Coleman Ratcliffe's strip joint, with Courtney a passenger in the car. Courtney starts working as a stripper to pay off A.J.'s debt and to keep A.J. out of trouble with the law. However, Sonny assigns Jason to be Courtney's bodyguard and Courtney slowly falls in love with Jason. A.J. burns down the strip joint when he learns that Courtney was stripping, but Jason pulls him out of the rubble. Hurt and angry that Courtney has fallen for his brother, "the golden boy," A.J. hires Ratcliffe, who is obsessed with Courtney, to stalk her. After various other financial and illegal misadventures, A.J. steals money from the Quartermaine family and leaves the country with heiress Lydia Karenin.

Kidnapping and death
A.J. resurfaces in 2005 with another plot to get Michael back. He hires Faith Rosco to kidnap Sonny's children. The two younger children, Kristina and Morgan are rescued by Jason Morgan, and Sam McCall, but Michael is presumed dead. A.J. plans to take Michael out of the country. Alan, who is sympathetic, initially helpes A.J. but turns him in after seeing A.J.'s willingness to commit violence to get his own way. When Jason tries to apprehend him, A.J.'s back is broken and he is hospitalized. While in the hospital, he is smothered by Dr. Asher Thomas, a man who he was blackmailing, for years ago having attempted to kill Jason at A.J's request. After A.J's murder, his son Michael is a suspect for awhile, but then eventually cleared.

Jason realized he had been wrong about his decision to help Sonny and Carly keep Micahel away from AJ because he had taken his brother's chance away to be a father and get to know who his son was. He apolgized to AJ and told him he would never get to be a part of his son Jake Spencer's life either. His regret over his decision increased even more after Michael was shot and fell into a permament coma because of Sonny and felt that with AJ he would have been safer.

His son Michael woke up from his coma in the summer of 2009. His ex-wife Carly Jacks asked his mom and grandfather if Michael can live in the Quartermaine house. The main reason why Carly didn't want Michael living there was because the Quartermaines backstabbed each other and bickered with each other.