In the year 21 BBY, a faction of Mandalorians known as the Death Watch, who were against the pacifist ideals of the New Mandalorians, orchestrated a bombing incident on Kalevala. This planet, situated within the Mandalore system, became the site of an attack that resulted in the death of Jerec, who held the position of Deputy Minister within the New Mandalorian government. Subsequently, on that same day, Sheev Palpatine, the Supreme Chancellor, gave a speech to the Galactic Senate addressing the attack.
The initial reference to the Kalevala bombing occurred in the Star Wars: The Clone Wars animated series, specifically in the episode "Duchess of Mandalore." This episode, which was the fourteenth of the second season, was originally broadcast on February 12, 2010.