The Aquilaris Massacre represents an assault orchestrated by the Chagras Hegemony against the Galactic Republic planet known as Aquilaris Minor. This event transpired in 1042 BBY during the period of the Republic Dark Age. The Chagras Hegemony itself originated as a splinter faction of the New Sith Empire, which had been engaged in a long-lasting war with both the Republic and the Jedi Order for almost a thousand years, dating back to 2000 BBY. Under the command of the Sith Lord Odion, Chagras forces effectively neutralized the planet's defenses, resulting in the deaths of numerous civilians and widespread destruction of the urban landscape. Among the survivors of this devastating event were Jedi Knight Vannar Treece and a Human girl named Kerra Holt. Inspired by her experiences, Kerra Holt later became a member of the Jedi Order, seeking to avenge the devastation inflicted upon her homeworld by Odion.

Aquilaris Minor once functioned as a resort destination within the Grumani sector. During the Republic Dark Age, it provided refuge to individuals fleeing Sith-controlled territories, eventually attracting the attention of the Chagras Hegemony, a Sith empire under the rule of Sith Lord Chagras. Chagras emerged as the sole survivor of the Charge Matrica, a conflict over succession initiated by his mother, Vilia Calimondra, who led the influential Calimondra family, a powerful Sith clan operating in the region. Throughout the duration of the New Sith Wars, Vilia entered into multiple marriages and established a substantial interstellar empire within the Grumani sector. Through these unions, she bore seven children, including Chagras and a daughter named Xelian.
Each of her offspring competed for the privilege of inheriting her empire. To resolve this competition, Vilia proposed a challenge known as the Charge Matrica, where the contender who successfully conquered the most territory would be designated as her sole heir. This conflict commenced in 1066 BBY and inflicted significant damage upon the Grumani sector and its surrounding areas. As time passed, this contest devolved into a family dispute among Vilia's children after Xelian declared war on Chagras due to the failure of her own campaign. Vilia refrained from intervening in this family feud, as she sought to eliminate any potential challenges to her authority. Around 1050 BBY, Chagras emerged victorious in the Charge Matrica and was designated as Vilia's successor. His triumph ushered in a period of stability within the Grumani sector and ensured Chagras the support of his nieces and nephews, whom he tasked with repairing the damage caused by the war within his holdings.
One of these nephews was the Sith Lord Odion, the eldest son of Xelian, who became one of his military leaders. By 1042 BBY, the Chagras Hegemony had recovered from the war and was prepared to challenge the Galactic Republic. Aquilaris was among the worlds targeted during this brief expansionist push. During a raid on the University of Sanbra, the Sith Lord Odion discovered that a team of academic researchers were collaborating with the Jedi Order on a project to locate the Helm of Ieldis, an ancient Sith artifact created by Lord Ieldis prior to the Great Hyperspace War. Following the invasion, the university researchers dispersed, with both the Jedi and Sith actively searching for them. Odion viewed the Helm as a potential asset in the internal Sith family feud that had destabilized much of the Grumani sector. Odion also learned that some Jedi were planning to meet twelve of these researchers on Aquilaris Minor.
Since Odion held a relatively junior position within the Chagras Hegemony, he required authorization from his superiors to launch the attack on Aquilaris. Odion secured approval from his grandmother, Vilia Calimondra, by falsely claiming that the raid's objective was to capture the Jedi Knight Vannar Treece, whose guerrilla attacks on Sith territory were undermining Sith control. However, Odion's true motive was to acquire the Helm for his own purposes. He withheld information about the Helm from his fellow Sith family members, intending to gain an advantage over them in any future conflicts. Due to his difficult upbringing, Odion had cultivated a deeply nihilistic perspective, advocating for the destruction of all life in the galaxy as a means of achieving peace.

Odion led a Chagras military fleet in an invasion of Aquilaris. Vannar Treece himself commanded the Galactic Republic defense of the planet, which included a fleet of Hammerhead-class cruisers. While specific details of the battle remain scarce, it is known that the Republic forces were overwhelmed by the invading Chagras forces under the command of Lord Odion. Sith forces, led by a lightsaber-wielding Odion, landed in the port city of Capital Cay and proceeded to massacre the civilian population, including throwing them into the water. However, he instructed his troops to avoid the block where the researchers were located, as he intended to capture them alive.
Future Jedi Knight Kerra Holt's parents Aron and Mercia Holt urged her to flee from the invading Sith in order to save herself. She fled to the docks, where she encountered her friend Joad Kreel, a young teenager whose father was a member of the Seacroppers' Guild and operated a submersible. Joad assured Kerra that he would wait for her while she retrieved her family, so they could escape underwater into the oceans of Aquilaris. However, he became frightened and left without her and his father who disappeared during the fighting. He managed to escape the harbor before it was bombarded by Odion's forces. Joad later returned to Capital Cay due to a lack of supplies and endured the Sith occupation. He remained with the Seacroppers' Guild but experienced poverty and starvation due to economic hardship and the Sith occupiers seizing the supplies of the local people.
Meanwhile, the Holts and the other researchers were captured by Odion's troops and forcibly enlisted in Project Pandemonium, with the goal of locating the Sith artifact known as the Helm of Ieldis. To conceal his secret mission, Odion ordered his forces to obliterate the residential block, destroying much evidence. Kerra returned to her home, where she encountered Vannar, whom she initially mistook for an intruder. However, she quickly recognized him as a Jedi and explained how her family had been forced to flee, expressing her uncertainty about where to go. Moved by her plight, Vannar informed Kerra that he had a starfighter hidden nearby and offered to help her escape offworld. He assured Kerra that they would return to Aquilaris when it was safe and that they would make it safe as Jedi.

During the subsequent Sith occupation of Aquilaris, the Sith enslaved the surviving population, including Joad Kreel, who was compelled to return to port due to a lack of alternative options. Odion carried out a massacre of most of the world's inhabitants, and Chagras eventually intervened, preventing his nephew from exterminating the entire population, so that some of the people could be used as slaves, to operate Aquilaris's fleek eel traps. Suspecting that Odion had an ulterior motive for invading Aquilaris, Chagras had Odion sent away from Aquilaris Minor. The Sith occupiers also seized the populace's homes and food, reducing the Aquilarians to a state of poverty and misery. Kreel spent much of his adolescence growing up in the Seacroppers' barracks, enduring squalid and unhealthy conditions.
To cope with the harsh Sith occupation, Kreel and many other Aquilarians became addicted to the spice Deluge, a narcotic that had been deliberately distributed by the pro-Republic Grace Command on Alderaan under Operation Deluge. Operation Deluge was a secret black operation initiated by the Alderaanian Baron Lemayne, an influential Republic intelligence official, to weaken the Sith war effort without diverting substantial Republic military resources from defending the Colonies and Core Worlds from further Sith incursions. Despite its successes, many of the civilian populations in Sith-occupied Space became addicted to the drug but Grace Command merely regarded them as necessary collateral damage in the Republic's war effort against the Sith.
Following the events on Aquilaris, Holt subsequently became a Padawan under Treece's tutelage. By 1032 BBY, she had passed her Jedi Trials and become a novice Jedi Knight. She subsequently served with distinction during the Chelloan affair where she helped fellow Jedi Gorlan Palladane evacuated around sixty thousand civilians from Chelloa prior to the destruction of its surface. Due to his experiences on Aquilaris and other worlds, Vannar also authored the holotract Those Who Drown which highlighted the plight of civilians in Sith-occupied Space. He also decried the general tendency within the Republic to blame the victims of Sith domination for not rising up to challenge their oppressors, citing they lacked the will and the strength to defend and free themselves from the Sith warlords. However, he still argued that they could be led to overcome their condition if the "way was lit by those who fight for good."

In late 1032 BBY, Kerra would subsequently return to Aquilaris Minor during the Aquilaris campaign following a distress call from the Seacroppers' Guild. In reality, this was a coded signal requesting more Deluge spice which had inundated the Grumani sector due to Operation Deluge. Following the death of Lord Chagras and the collapse of his empire, the planet had come under the Sith Lord Daiman, Odion's estranged younger brother and had declined economically due to the collapse of trade and the dictatorial tendencies of Daiman. Aquilaris attracted the attention of three rival parties with vested interests during a three campaign involving Daiman's princedom, Hutt crimelord Zodoh's empire, and the Galactic Republic and Jedi Order represented by Grace Command's Captain Jenn Devaad and Kerra Holt respectively.
The Sith Lord Daiman had recently acquired the planet in the ensuing power vacuum following the collapse of the Chagras Hegemony. Zodoh had wanted to expand into traditional Sith Space by using his new Stormdriver superweapons to intimidate his Sith rivals. First, he intended to test them on Aquilaris Minor by using their weaponized vaporators to submerge the planet in water. Meanwhile, Grace Command had intended to drive out the Sith while secretly inundating the population with Deluge as part of Operation Deluge. In contrast, the Kerra Holt had planned to liberate the planet from Sith occupation and rescue the Aquilarians from the machinations of both Zodoh and the Sith.
Zodoh and Grace Command wiped out Daiman's meager garrison, with the latter taking control of the planet. Zodoh's forces retreated into the far reaches of the Aquilaris system but lured Devil Squadron into a trap. The entire squadron with the exception of Captain Jenn were killed. Zodoh then proceeded to test his fleet of Stormdrivers on Aquilaris, creating a global flood which inundated much of the surface in water. Subsequently, Jenn managed to escape and disrupted the coordination of the Stromdrivers in the process. Despite this minor setback and the destruction of stocks of Deluge spice during the escape, Zodoh regarded this as a victory since it had proven the effectiveness of his superweapons. He then dispatched his fleet to Darkknell, capital of Daiman's princedom. He was ultimately defeated and slain during the battle.
Meanwhile, thousands of lives on Aquilaris were saved through the efforts of Kerra with the assistance of local Seacroppers Joad and Padgett, who managed to evacuate many civilians in submersibles to underwater harvester stations. After the events of the Aquilaris campaign, Devaad and Holt came up with a strategy to sabotage Operation Deluge. Devaad would return to Grace Command and claim that she had gotten a contract for distributing the Deluge on Aquilaris. This ensured that Grace Command would continue to send transport ships which Devaad would personally fly to and from Sith occupied words. En route, she would dump the Deluge into hyperspace while returning to the Republic with civilian refugees. With the hidden undersea facilities on Aquilaris, the world could even become a important hub for ferrying refugees from Sith occupied space to safety in the Republic.
The initial depiction of the Aquilaris Massacre occurred within Knight Errant: Aflame 2, which was released on November 10, 2010. Its primary role was to elucidate the motivations and sentiments influencing the central character, Kerra Holt. Furthermore, it introduced the planet Aquilaris Minor, whose detailed history was further developed in the second comic arc, Star Wars: Knight Errant: Deluge, which spanned from August 17 to December 21, 2011.