Warning: The following contains spoilers from Star Wars: War of the Bounty Hunters #5, on sale now from Marvel Comics.
At the beginning of Star Wars: Return of the Jedi, it’s very clear that Jabba the Hutt was an immensely powerful figure. Owning his own pocket of the galaxy called Hutt Space, Jabba was the premier crime lord at that time, and he had a hand in almost every criminal dealing that happened in the galaxy. However, there were countless Hutts in Star Wars history, so the question that should arise is how Jabba consolidated power. A definitive answer to that question was given in Star Wars: War of the Bounty Hunters #5 by Charles Soule, Luke Ross, David Messina. Rachelle Rosenberg, Neeraj Menon, and VC's Travis Lanham.
In the War of the Bounty Hunters crossover event, Crimson Dawn stole Han Solo from Boba Fett while the bounty hunter was en route to Tatooine. Because of that, Jabba was forced to bid for Solo at a galaxy-wide auction, and he won. However, Vader interrupted the auction and took Solo for the Empire, leaving Jabba empty-handed.
Jabba saw the bigger picture and preserved his relationship with the Empire by letting Solo go, but a younger Hutt, named Bokku, was embarrassed that Jabba would let the Empire insult the Hutts in such a fashion. So, after Jabba left Crimson Dawn’s ship, Bokku whipped up the Hutt Council and, with a grand speech, made them agree to attack the Empire.
Thus, as a shuttle transported Solo to Vader’s Star Destroyer, Bokku put the entire Hutt fleet into attack formation and moved in on the Empire. This attack was motivated by Bokku’s pride as a Hutt, but he was also secretly a member of Crimson Dawn. Once Qi’ra told him to attack and, if necessary, sacrifice himself for their cause, he didn’t hesitate and commenced the foolhardy attack.
While that was happening, Vader was off chasing Luke through the sky in his TIE fighter, having given strict orders to not be disturbed. However, when Admiral Piett saw the Hutts, preparing to attack, he made use of Vader’s one loophole. The admiral contacted Emperor Palpatine directly and received orders for Vader to personally take care of the situation and send a permanent message to the Hutts.
While annoyed with having to abandon the chase for Luke, Vader, nonetheless, was determined to obey his master. So, he boarded Bokku’s flagship and brutally killed the entire Hutt Council in a scene that was reminiscent of when Anakin killed all of the Separatist leaders on Mustafar. With Bokku and the rest of the council disposed of, the Hutts were no longer a threat.
That being said, Palpatine still wanted to maintain an alliance with the Hutt Empire. So, with all of the other ruling Hutts dead, Jabba assumed unquestioned control of all of their criminal enterprises. Since he was deferential to Vader during the auction, he started off on the right foot, and after what happened to Bokku, Jabba continued to play nice with the Empire thereafter. It was a great situation for Jabba as the sole ruler of the Hutt Empire, until everything came crashing down when he was killed by Leia on his own sail barge.