The clash known as the Battle of Wasted Years took place around 1032 BBY. Darth Krall, a Sith Lord, participated in this conflict, ultimately achieving victory. The account of Krall's triumph in this battle was recorded within the holojournal belonging to Klias Teradine. Teradine was a Jedi Padawan during the High Republic Era who met his death in 241 BBY at the hands of Tylera Yorrick, a fellow Padawan. Yorrick was possessed by a vitalicron at the time, though many Jedi later theorized he had been expelled from the Jedi Order.
In 88 BBY, Sifo-Dyas, a Jedi Initiate, shared information with Dooku, another Initiate, regarding Teradine's holojournal and the details it contained about Darth Krall's actions, including the Battle of Wasted Years. Subsequently, Dooku recounted this conversation to Jenza, his sister, in a holo-letter. Approximately around 23 BBY, Dooku entrusted Asajj Ventress, his newly appointed Sith assassin, with data disks holding his messages to Jenza, for her investigation to find his sister's location. She then listened to the message where the battle was mentioned.
The audio drama Dooku: Jedi Lost, penned by Cavan Scott, marked the initial mention of the Battle of Wasted Years. It was released on April 30, 2019. The capitalization of the name was later verified upon the release of the script on October 1 of that same year.