The conflict known as the Battle of Haruun Kal unfolded on the planet of Haruun Kal during the Clone Wars in the year 19 BBY. Leading the Galactic Republic's clone trooper forces was Jedi General Depa Billaba, who commanded her designated battalion. They faced off against the opposing forces of the Confederacy of Independent Systems. General Grievous, the Separatist commander, orchestrated a devastating assault. This resulted in a staggering ninety percent death rate among Billaba's troop complement, securing a decisive victory for the Confederacy. In a personal duel, Grievous overpowered Billaba in lightsaber_combat, leaving her in a prolonged coma for a duration of six months as she recovered from her severe injuries. Upon her eventual recovery, she was placed in command of a new battalion of soldiers, but the memory of her failure at Haruun Kal continued to affect her for a significant time.
During the period of the Clone Wars, Haruun Kal became a significant battlefield as units of the Grand Army of the Republic and the Confederacy of Independent Systems' military engaged in combat on the planet. Jedi High Council member Depa Billaba, a Jedi General, oversaw the Republic infantry forces. Her battalion of clone troopers encountered formidable opposition in the form of Confederate General Grievous. Grievous's forces inflicted heavy losses on Billaba's troops, resulting in a ninety percent death rate within her unit. Only four soldiers managed to survive the devastating conflict: Commander Grey, Captain Styles, Sergeant Soot, and Corporal Big-Mouth.
In the meantime, Grievous engaged Billaba in a one-on-one lightsaber_combat, ultimately defeating her and inflicting severe injuries that rendered her comatose. Although Grievous was unable to confirm her death, the Confederacy eventually acquired intelligence confirming her survival and incorporated it into their records.
Due to the Republic's substantial losses, Confederate forces declared victory on Haruun Kal. Billaba was transported back to the Jedi Temple located on Coruscant, the Republic's capital, where she received medical attention. Some of her surviving men, including Styles and Grey, felt responsible for her defeat at Haruun Kal and vowed to prevent such a failure from happening again.
Billaba remained in a coma for six months, after which her fellow Jedi Masters assessed her condition and permitted her to resume her position on the Jedi High Council. Her defeat at Haruun Kal not only damaged her reputation as a military commander but also diminished her confidence as a general, forcing her to grapple with the guilt of losing so many of her men. Nevertheless, she played a role in preventing a Separatist attack on the Jedi Temple and returned to military service with a new Padawan, Caleb Dume. Grey, Styles, and the other survivors from Billaba's previous unit became the commanding officers of her new battalion within the Grand Army.
The Battle of Haruun Kal was conceived as part of the background narrative for Star Wars: Kanan, a canon comic series published by Marvel Comics. Writer Greg Weisman elaborated on the details of the battle for the series' second story arc, First Blood. Initial references to the battle appeared in the story arc's first issue.
The storyline involving Depa Billaba entering a coma following a battle on Haruun Kal originated in Shatterpoint, a Star Wars Legends novel authored by Matthew Stover and released in June of 2003.