Battle of Dathomir

Asajj Ventress had been the Sith apprentice of Count Dooku since the beginning of the Clone Wars. She successfully led Separatist forces against the Galactic Republic during multiple battles and engagements. However, during the Battle of Sullust, Count Dooku was contacted by his Sith master Darth Sidious. Sidious believed that Ventress had grown too powerful, and believed that she was being trained to be used against him so Dooku could take power, in line with the Sith Rule of Two. While Dooku denied this, Sidious ignored him and ordered the Count to eliminate Ventress to prove that his allegiance did belong to the Dark Lord of the Sith alone. Dooku was forced to agree to kill Ventress. While the battle raged on between the Republic and Confederate fleets, he called off her reinforcements, and ordered the T-series tactical droid TJ-912 to fire on the ship Ventress was on, where she was dueling Dooku's nemesis Jedi General Anakin Skywalker and Master Obi-Wan Kenobi. Following this, Dooku informed Ventress by hologram that she was no longer his apprentice and retracted her reinforcements because of her failing him for the last time and would die.

Despite Dooku's scheme, Ventress managed to survive and escaped from both the Jedi and the Confederacy. Having left Dooku and the Separatist cause, she returned to her homeworld of Dathomir, where she rejoined the Nightsisters and began to make plans to kill Count Dooku as her revenge.

Dooku, having learned that Ventress had returned to Dathomir, sent the Supreme Martial Commander of the Separatist Droid Armies, General Grievous, and a Separatist fleet carrying an army of battle droids to finally exterminate Ventress, Mother Talzin, and the Nightsisters for vengeance against them as well as Lord Sidious seeing Ventress' kinfolk as a threat to his new evil empire.

Upon the arrival of General Grievous and his forces, Ventress had completed her initiation, and had become a full Nightsister.

Grievous' squadron of Vulture-class starfighters and Hyena-class Droid Bombers bombed the Nightsisters' fortress and force them out of hiding.

His fleet of four Munificent-class star frigates, two Recusant-class light destroyers, two Dual Hemisphere-Omni Support Vessels, and his personal Providence-class Dreadnought, Grievous and his forces traveled to and exited hyperspace in the Dathomir system, and landed on the planet.

To aid her fellow Nightsisters at the front lines, Old Daka recited the Chant of Resurrection to rise the Army of the Dead, gaining an army of undead Nightsisters.

Upon arrival, Grievous ordered his crew of OOM-series security droids to launch the invasion by beginning to land their troops on the planet below. Grievous sent out a force of BX-series droid commandos, B1-series battle droids, B2-series super battle droids, IG-100 MagnaGuards, a Defoliator Deployment Tank, and Multi-Troop Transports.

After controlling the front lines, Grievous' forces pushed the Nightsisters back to their fortress. After killing most of the Nightsisters, Grievous stormed the fortress and knocked down the wall to get into the Hidden Cave. He impaled Daka and knocked over her ichor cauldron, stopping Dooku's voodoo torture. With Daka's defeat, the zombie Nightsisters were defeated as well, leaving the living sisters to be massacred by the Droid Army. Through a combination of its red-colored environment and the wreckage strewn about it after the battle, Dathomir was left a wasteland.

With Ventress on the run and the loss of their undead reinforcements, the remaining Nightsisters were scattered throughout the forests, pursued by hordes of battle droids. Many, including Morgan Elsbeth and her mother Selena were among a group of Nightsisters being pursued by many of Grievous' droids. As the sisters prepared to make their final stand, they were ambushed by Grievous himself, who chose to face Selena alone while commando droids faced down Morgan and the group of Nightsisters. After striking down Selena and mockingly yelling at Morgan to run, Grievous ordered his forces to annihilate the remaining Nightsisters, leaving the landscape a burning wasteland.

With the battle over and her fellow Nightsisters murdered, Ventress moved before being met by Talzin, appearing as a spirit. Ventress blamed herself for the destruction, and Talzin told her that, though the Nightsisters would always be linked to her, she now had her own path. Ventress begged Talzin not to leave her, but the Nightsister mother did just that. Thus, Ventress made her way off Dathomir. Talzin remained on the planet and kept in contact with her sons Maul and Savage Opress. A dying Daka sent the nightsister Yenna off-planet in an escape pod. A young Merrin and Jerserra mourned the death of their sisters, with the former burying the clan's members including her best friend/romantic interest, Ilyana. At least one Nightsister completely avoided the devastation of her people by being located offworld: Shelish, who had left Dathomir in her youth years prior, sought to honor their memory after the massacre.

Following the events of the battle, Ventress felt that her connection to the Force was scattered. In pursuit of the new life Talzin had foretold, Ventress travelled far into the Outer Rim, eventually ending up on the desert world of Tatooine. When Ventress arrived in a cantina on Tatooine, she realized no one in the building knew that her people had been slaughtered, with Ventress considering the Battle of Dathomir to be the effective end of her homeworld. After taking part in safe cargo objective, she remembered Talzin's final words to her, though now without the same feeling of pain. Instead, she believed she had always had a path and that, after losing it for some time and becoming so many things throughout her life, she was herself, with the entire galaxy waiting for her. She proceeded to take up the life of a bounty hunter.

To route out any surviving Nightsisters, Grievous deployed patrols of HMP droid gunships, probe droids and battle droids across the forests and mountains following the battle to hunt down anyone that might have survived the Separatist invasion.

Over the years and decades that followed, those who survived, having witnessed their sisters slaughtered by an armored warrior brandishing a lightsaber whose identity no one knew, waited for the right moment to swear to seek vengeance to avenge their fallen sisters. During the Imperial Era, Jerserra was found by a female Inquisitor who trained her as a dark-sided Force user. While showing the young Jedi Ezra Bridger the ruins of the Nightsister lair, Maul stated that the Nightsisters would have been a threat to the Galactic Empire and that was why they were destroyed.

Morgan Elsbeth was another survivor, witnessing her mother Selena's death, then staying low after defeating the droids in her vicinity. She would later pledge allegiance to that same Empire, helping to build and expand the Imperial Starfleet at the expense of the worlds she plundered for their resources and pursue power and revenge after the genocide of her people left her embittered. Although her heritage as a Nightsister was questioned, Elsbeth deemed herself a survivor and would endeavor into the era of the New Republic, where she sought to find her lost master, Grand Admiral Thrawn, and restore him from his exile in a far galaxy.

The Battle of Dathomir was created for the Star Wars: The Clone Wars television series and was featured in the episode "Massacre," which aired on February 24, 2012 as part of the series' fourth season. In December 2012, StarWars.com ranked the Battle of Dathomir as the third most memorable moment of the television series from 2012.

The Battle of Dathomir also recieves a mention within the 2017 video game Star Wars Battlefront II through its character DLC. When a player is able to spawn into an ongoing match as Grievous, there is a chance the general will remark "this will be easier than Dathomir!" as his first line.