The conflict known as the Battle of Nar Shaddaa transpired by 68 BBY on the lunar body of Nar Shaddaa. During this battle, Crucitorn, a Jedi Master belonging to the Jedi Order, engaged in combat with the Flame-Wielders. The Flame-Wielders set Crucitorn ablaze, but he persisted through the agony and retaliated. In the year 68 BBY, Dooku, also a Jedi Master, referenced these events when explaining to Qui-Gon Jinn, his Padawan, the vital importance of mastering the Force to withstand physical pain for a Jedi.
Subsequently, Dooku communicated to Jenza, his sibling, about his discussion with Jinn via a holographic message. Around 23 BBY, Dooku entrusted several data storage devices containing his communications to Jenza to Asajj Ventress, his newly appointed Sith assassin, so she could investigate the whereabouts of his sister. Ventress then listened to the holo-disk that made mention of the Battle of Nar Shaddaa.
The audio drama Dooku: Jedi Lost, penned by Cavan Scott and released on April 30th, 2019, featured a mention of the Battle of Nar Shaddaa in a flashback sequence. The precise capitalization of the battle's designation was verified by the audio drama's published script on October 1st of the same year.