Scottish native Duke Lavery arrived in Port Charles in 1986 and was instantly attracted to police commissioner and former WSB agent Anna Devane. The feelings were mutual but Anna sensed that the nightclub owner was hiding something from her. Her instincts were correct, as Duke was secretly an associate of mobster Mr. B and used the nightclub to launder money. Duke's feelings for Anna grew, and he decided to leave the mob in order to pursue a future with her. The other members within the organization did not support Duke's decision and threatened the home Anna shared with her daughter.

Word of the threat of danger to Anna and her daughter reached Anna's former husband Robert Scorpio and he returned to town. Robert suspected that Duke was involved in organized crime and Duke decided to seek help to end his ties to the mob. He reached out to mobster Angus McKay, who had Scottish ties, unaware that Angus was actually his father. Angus promised to help Duke but instead used him to gain a foothold in organized crime within Port Charles.

Once Duke realized that Angus had duped him, he joined the fight against the two mob rivals and took a bullet meant for Robert which left him temporarily paralyzed. Duke confessed to his crimes and served a brief amount of time in prison. Angus was also imprisoned but chose to kill himself by drinking poison. Shortly before his death, Angus revealed that he was Duke's father and announced that Duke had a half-sister named Camellia. Duke vowed to look after her. Duke knew Camellia as they had been involved in a relationship in the past but was shocked to learn that they were related.

After Duke completed his time in prison he tried to move forward with Anna but his past with Camellia halted the relationship. Anna suspected that something was not right between Duke and his half-sister and Duke admitted that he had previously dated her. Eventually Camellia learned that she was not related to Duke and she tried to rekindle the romance they once shared but Duke remained in love with Anna and they made plans to marry.

As Anna and Duke moved forward with their wedding plans they were unaware that a reporter looked into Duke's past with Camellia. On the day of the wedding reporters interrupted the ceremony and announced that Duke had helped Camellia cover up a murder several years before in L'Orleans. The man she had murdered was a member of the Jerome crime family. Anna walked away from Duke and opened a private investigation business with her former husband. Robert tried to win Anna back but her heart belonged to Duke and they eventually reconciled and were married.

Duke was pulled into the mob once again when Anna was kidnapped. He turned to Victor Jerome for help and Victor's son was killed after he took a bullet intended for Duke. Victor helped Duke find Anna but in return required Duke to take his son's place within the Jerome family organization. Once Anna was safely home Duke hid his return to the mob while Olivia Jerome arrived in Port Charles and set her sights on mob power and on Duke.

Olivia tried to seduce Duke but he remained faithful to Anna and was thrilled when Anna announced that she was pregnant. Eventually Olivia realized that neither Duke nor his role within her family would ever be hers and she planned to kill Duke. Olivia rigged an elevator to crash but Anna entered instead of Duke. She survived the fall but her unborn child did not. Afterwards, Duke testified against Olivia and revealed his mob association.

After Duke testified he became the target of the other mobsters and Duke worried about the safety of Anna and her daughter. He decided the best way to protect them was to fake his own death and enter the witness protection program. Duke led everyone to believe that he had perished in a warehouse fire and then disappeared on an airplane headed for an unknown destination.

Duke claimed that he had been taken by the Jerome family and held in a Turkish prison. His cellmate was a man named Jonathan Paget. The two men passed the time by trading stories and Duke shared his detailed memories of his life with Anna, unaware that Jonathan was working undercover and had been assigned to learn about Duke's life in order to impersonate him. Jonathan surfaced in Port Charles without Duke's face or accent but used Duke's memories to convince everyone that he was Duke. However, Julian Jerome shot Jonathan and he died in Anna's arms. She believed it was Duke that had died.

In 2012, "Duke" resurfaced in Port Charles and reached out to Anna in an attempt to restore the life they once shared. When "Duke" was away from Anna, he behaved differently and committed several crimes. It was later revealed that Cesar Faison had impersonated Duke while he held the real Duke Lavery captive.

Duke was overjoyed to be reunited with Anna but she held him at bay. Although Anna knew it was the real Duke in front of her, she remained disturbed by her experience with Faison. Anna was also torn between her feelings for Duke and Luke Spencer. Duke opted to give Anna space to sort out her feelings. In the meantime, he took a position working for A.J. Quartermaine at ELQ. Anna did choose to explore a relationship with Duke and they both agreed to get reacquainted in the present in the hopes that they may find the magic they had shared in the past.

Duke and Anna grew closer as they agreed to be attendants in Felicia's wedding to Mac. On the eve of the wedding, Duke was hospitalized after he ingested a sedative that Dr. Liesl Obrecht had placed in a drink. Anna kept vigil at his bedside until he regained consciousness. When he awoke, they declared their love for one another and Duke told Anna that Dr. Obrecht, the same woman that had helped Faison hold him captive in Switzerland, had poisoned him. Anna vowed to make Dr. Obrecht pay for her crimes.

After Duke's hospitalization, he was forced to find a new job after Tracy regained control of ELQ. He took a position as the Chief of Staff for Derek Wells, a wealthy businessman that had recently moved to Port Charles. Duke sensed that his new employer had secrets and planned to watch Derek carefully. At the same time, the name Julian Jerome resurfaced within organized crime and Duke wondered if his former enemy could still be alive.

Meanwhile, Duke started to worry about Anna after she left town in pursuit of Faison. When Duke looked into Anna's possible whereabouts, he was taken captive at Wyndemere by Faison. Anna tracked Faison to Spoon Island and rescued Duke and shared the news that Robin was alive. He was overjoyed but it was tempered by the revelation that Derek Wells was actually Julian Jerome. Duke immediately cut ties with Julian and promised Anna that he would stay away from organized crime. However, Duke secretly agreed to help Sonny Corinthos take down the Jerome organization after he overheard Julian threaten Anna.

Duke and Sonny developed a friendship as they worked together to dismantle the Jerome organization. The secret alliance between the men caused a strain on Duke's relationship with Anna and she demanded that Duke sever his ties with organized crime. Duke and Sonny parted ways as friends and Duke continued to lie to Anna on Sonny's behalf. Duke provided a false alibi for Sonny on the night A.J. Quartermaine was shot. Anna questioned the validity of his statement repeatedly and Duke continued to protect Sonny. Anna was forced to arrest Duke after his statement was proven to be false.

Although Duke's attorney recommended that he turn on Sonny, he remained loyal and was taken to Pentonville to await his trial. Sonny respected Duke's actions and made a plea bargain which resulted in Duke's freedom while Sonny went to prison. Duke agreed to run the organization in Sonny's absence despite the cost to his relationship with Anna. He reasoned that what he and Anna had shared was over since she was unable to forgive his need to step outside of the law to deal with Julian even though she had taken the same path with Faison.

Although Duke remained in love with Anna, he and Lucy became lovers while he ran Sonny's business. Upon the recommendation of Sonny's enforcer Shawn Butler, Duke brought Jordan Ashford into the organization after she left the Jerome syndicate. He was disappointed to learn that Jordan was working undercover for the police and he quietly made plans to have Jordan killed. Meanwhile, Lucy ended the romantic side of her relationship with Duke and encouraged him to reunite with his true love Anna and Lucy arranged for Duke and Anna to tango at the Nurses Ball. Afterwards, Duke and Anna declared their love for one another and made plans to run away from Port Charles together and Duke called off the hit on Jordan.

Before Anna and Duke were able to make their escape, Julian Jerome's associate Carlos Rivera found Duke and shot him. Duke was gravely injured but managed to meet Anna at the rendezvous point. She begged Duke to pull through so they could begin their new life together but he succumbed to his injuries and passed away.