In the year 44 ABY, Gavar Khai, a Sith Saber, conceived a scheme known as the Jedi Queen project. This plan centered around the assassination of Tenel Ka Djo, the Queen Mother of Hapan, with the goal of averting the birth of a future galactic queen of Jedi heritage, who was anticipated to wield significant power. Querdan Dei, another Saber, was entrusted with this mission and tracked the Hapan queen to the planet of Klatooine. However, he met his end in lightsaber combat at the hands of Leia Organa Solo, a Jedi Knight, suffering a fatal blow.
During 44 ABY, Sarasu Taalon, the High Lord of the Lost Tribe of Sith, received a vision: a young Human queen ruling the galaxy under the banner of the Jedi Knights. Obsessed with preventing a Jedi monarch from ascending to a galactic throne, Taalon's life was cut short in battle before he could enact his scheme, resulting in his death. Gavar Khai, a Sith Saber and frequent ally of Taalon in recent battles against the Jedi, resolved to carry out his fallen commander's ambition. He designated the plot as the Jedi Queen project. The Sith discovered that Tenel Ka Djo, the Hapan Queen Mother, bore a resemblance to the future Jedi queen, leading them to fear she would give birth to her. Little did they know, she already had a daughter, Allana Solo, disguised as "Amelia," the adopted daughter of Han Solo, a pilot, and his wife, Leia. In a misguided attempt to prevent a future that had already materialized, Khai tasked Querdan Dei, another Sith Saber, with the assassination of Djo.
Dei, accompanied by his crew—Hara, Sazat, and his son, Fardan—embarked on a journey aboard the Cryptic Warning, an EE-104 Fisheye, to the Hapes Consortium. Their objective was to infiltrate the Queen Mother's domain and kill her. The Sith detected a fleet of Hapan Battle Dragons en route to Klatooine, a planet, with Tenel Ka Djo aboard. Querdan Dei and his team shadowed the vessels to Klatooine, where they also discovered the presence of the Millennium Falcon. Observation of the Klatooine camp revealed it to be an unsanctioned mission aimed at negotiating terms following the planet's recent uprising against their former Hutt overlords. Dei conducted reconnaissance around the camp, devising a strategy to accomplish his mission.
Dei seized C-3PO, a droid belonging to the Solo family's, and concealed a bomb within him. Subsequently, Dei bribed a 2-1B surgical droid from a droid rights advocacy group to stage a capture of C-3PO. Amelia, the Solos' supposed adopted daughter, discovered the droid and rescued it from the droid rights group, bringing it along to assist Djo with translation. Dei intended to detonate the droid once it was in close proximity to Djo. However, as he waited, he came to suspect that Amelia was actually Djo's daughter, given their striking resemblance. Dei decided to eliminate Amelia as well. Just as C-3PO was in position, Dei reached for the detonator to activate the bomb. However, Amelia had stealthily approached him and seized the remote. Dei demanded its return, and though she refused, he confirmed that Djo was indeed Amelia's mother.
The Sith Saber lunged at young Amelia with his lightsaber, but before he could inflict harm, he was intercepted by Anji, the girl's pet nexu. Anji clawed out his eye before he could shake her off. As he prepared to resume his attack on Amelia, he was confronted by Leia Solo. She demanded his surrender, but he refused, and they engaged in lightsaber combat. The duel persisted for several minutes, but ultimately, Dei's spin caused him to lose sight of Solo due to his newly missing eye, allowing her to deliver the killing blow.
Shortly thereafter, a larger Sith contingent under Gavar Khai's leadership failed in their mission to capture Abeloth, a potent dark side entity, on Nam Chorios. Following the battle, Abeloth contacted Khai, proposing an alliance against their shared adversary, the Jedi. Khai agreed, only for Abeloth to betray the Sith soon after, destroying their capital city, Tahv. Khai succumbed to Abeloth's influence and defected from the Sith, joining her forces instead. Despite retaining interest in preventing the Jedi queen's rise, Abeloth forbade him from pursuing the Jedi Queen project further.
The conceptual foundation for the Jedi Queen project was initially established in Fate of the Jedi: Vortex, the sixth installment of the nine-part Fate of the Jedi series by Troy Denning, featuring Taalon's vision of the Jedi queen and his subsequent demise. The project was formally named and executed in Fate of the Jedi: Conviction, the seventh novel in the series by Aaron Allston. The project received only a passing mention in the eighth novel, Fate of the Jedi: Ascension by Christie Golden, where Abeloth officially terminated it.