Warning: The following contains SPOILERS for The Book of Boba Fett.
The Book of Boba Fett season 1 finale hinted at the backstory between Cad Bane and Boba Fett, though the details of the Star Wars timeline centered around them were kept vague. The two bounty hunters have a surprisingly long history of working together. However, this history has largely been alluded to, with most of the actual events having yet to be depicted in any medium.
While Boba Fett's history up until the events of Return of the Jedi is well established, the sinister Cad Bane remains a figure of mystery. First appearing in the Star Wars: The Clone Wars season 1 finale, "Hostage Crisis," Bane was part of a group of bounty hunters sent to break Ziro the Hutt out of prison. He remained a figure of menace throughout the series' run, proving himself capable of besting both Jedi and Clone Troopers in a fight.
The Book of Boba Fett finale affirmed that Cad Bane had served as a mentor to Boba Fett, with the elder mercenary commenting that he had beaten Boba on jobs before and had a "final lesson" to teach him. The episode also confirmed Cad Bane as a contemporary of Jango Fett, as he remarked that Boba had the same killer instinct as his father. This proved to be unfortunate for Cad Bane, whom Boba Fett killed during their duel in the episode's climax. This ended the long conflict between the two bounty hunters, but the episode said nothing about where their animosity began.
Cad Bane's History With Jango Fett In Star Wars
Little has been written about Cad Bane's origins beyond his being a native of the planet Duro, where he was born 62 years before the Battle of Yavin. How he came to leave his homeworld and become a bounty hunter is unknown but it has been chronicled that Jango Fett mentored Cad Bane at some point early in his career, sometime before the start of the Clone Wars. This detail was revealed in Jango's biography in Star Wars Helmet Collection #41. Whenever this occurred, Cad Bane proved an apt pupil and was widely considered to be the best bounty hunter in the galaxy following the death of Jango Fett during the First Battle of Geonosis.
When Did Cad Bane & Boba Fett First Meet?
Boba Fett and Cad Bane's first meeting has yet to be explored by any piece of Star Wars media. However, Boba Fett clearly knew Cad Bane and had worked with him enough at some point while his father was still alive to have a good opinion of the ruthless bounty hunter. This was confirmed in the 2019 comic Age of Republic - Jango Fett #1, in which a young Boba complained to his father about working with some less infamous bounty hunters rather than teaming with Cad Bane, at some point before the start of the Clone Wars.
When Cad Bane Started Mentoring Boba Fett As A Bounty Hunter
The only recorded instance of Cad Bane and Boba Fett working together came in Star Wars: The Clone Wars season 4, episode 15, "Deception." The events of the episode centered around Obi-Wan Kenobi, as he went undercover in a Republic prison to try and uncover information regarding a Separatist plot to assassinate Chancellor Palpatine. While he was there, he was assaulted by Boba Fett, who was later revealed to have been recruited by Cad Bane to create a distraction so that he and his ally Moralo Eval could enact their escape plan unnoticed.
While Cad Bane and Boba Fett did not appear on-camera together, Star Wars: The Clone Wars season 4, episode 15 confirms that the two had a working relationship while in prison. It had been theorized by some Star Wars fans that Bane later took a young Boba Fett under his wing and trained him in the bounty hunter's craft, in honor of Boba's father Jango Fett, who had mentored him when he first started as a bounty hunter. This was also suggested by Boba Fett's biography in the book Star Wars: The Galactic Explorer's Guide, which noted that Boba had trained with several legendary rogues before forming the bounty hunter syndicate Kryat's Claw. It seemed likely that Cad Bane was one of these rogues and The Book of Boba Fett finale seemingly confirmed the fan theory.
Cad Bane & Boba Fett's Cut Clone Wars Arc & Duel Explained
The history between Boba Fett and Cad Bane would have been confirmed by a story arc in Star Wars: The Clone Wars. Unfortunately, the series was cancelled before the episodes could be completed. This untold tale was revealed by Dave Filoni, who was the Supervising Director of Star Wars: The Clone Wars as well as a director on both The Mandalorian and The Book of Boba Fett.
Filoni first described the aborted arc, which would have focused on Boba and Cad's relationship and how they came to blows over ethical issues, during a panel at Star Wars Celebration Orlando 2017. The panel also included a brief clip of unfinished animation, which showed the two bounty hunters enter into a duel with one another. The canonicity of this scene is debatable and The Book of Boba Fett does not make direct reference to it. However, there is a similar dramatic resonance between the unfinished animation and the final battle between Boba Fett and Cad Bane in The Book of Boba Fett. It is also worth noting that the scene would explain the cybernetic patch on the back of Cad Bane's head, which he did not have during Star Wars: The Clone Wars but did have in Star Wars: The Bad Batch.
Why Boba Fett Kills Cad Bane
While Boba repeatedly showed mercy to those who stood against him and took many of them into his service, like the Wookie bounty hunter Black Krrsantan, he knew Cad Bane well enough to know his old teacher would see such a display as weakness. He also knew Cad Bane was too much of a professional to back off of a job once hired. The only way the conflict between student and mentor could end would be with blood and while Boba Fett may have regretted having to kill his mentor, he did not hesitate in doing so when push came to shove. Given that The Book of Boba Fett was all about Boba's efforts to get away from his murderous past, his killing Cad Bane would seem to be a relapse into old habits. However, Boba's actions make perfect sense within the larger context of his history with Cad Bane as chronicled in other Star Wars media.