Baltizaar was a Mid Rim planet within the Galactic Republic to which a Jedi team was sent prior to the Invasion of Naboo in 32 BBY, in response to an attack by forces of the Bando Gora. Dooku chafed at the indiscrimination employed by the Republic in assigning Jedi to such missions; immediately prior to its departure, he left the Jedi Order, becoming the latest of the Lost Twenty. However, the Jedi did not realize at the time that he was already Darth Tyranus; the task force was subsequently decimated by the Bando Gora on Baltizaar.
Most of the surviving Jedi returned to Coruscant, but in the aftermath Dooku's former Padawan Komari Vosa fell to the dark side of the Force. Vosa fell to the dark side after having been captured and cruelly tortured by the Bando Gora, whose leaders she eventually replaced after brutally killing them.