Jebevel Madon held the position of Supreme Chancellor within the Galactic Republic, taking over from Leontyne Saresh in the year 3632 BBY due to her term expiring. Saresh tried to get rid of these term limits so she could stay in power forever, but the Shroud, a secret agent, secretly stopped her plans. However, Jebevel Madon didn't really have much power and was mostly controlled by Saresh. In 3630 BBY, after Saresh tried to take over the Alliance, the Chancellor contacted the Commander, revealing her disapproval of Saresh's schemes and secretly backing the Outlander. Subsequently, Chancellor Madon stepped down from her role, leading to the election of Galena Rans, the spouse of the retired Supreme Commander Rans, as the new Chancellor following Madon's departure.
A news report featured in the flashpoint "A Traitor Among the Chiss" reveals that Chancellor Madon had resigned and that Galena Rans was serving as an interim chancellor for the Republic; this occurs if the player chose to eliminate Jace Malcom during the Iokath narrative.