Lady Brezwalt III held the esteemed position of High Lady within House Mecetti, concurrently leading the Mecrosa Order. Her reign occurred during the era that culminated in the significant historical event known as the Cleansing of the Nine Houses. As a member of the Mecetti lineage, she was part of a long line of rulers within the Tapani Empire.
With the eruption of the Great Sith War, High Lady Brezwalt saw this as a chance to expand her House's imperialistic goals within the sector. During the Tapani Day celebrations, she ordered her Sith assassins from the Mecrosa Order to simultaneously eliminate the leaders of five of the eight rival houses. House Pelagia was the only house that managed to thwart the assassination attempt. The territories belonging to Houses Calipsa, Melissus, Barong, and a portion of Reena were then annexed into Mecetti Province.
Pelagia and Melantha made appeals to the Republic for intervention, but the Republic's resources were already strained due to the escalating war led by the Sith Lord Exar Kun. Sith Lady Brezwalt was on the verge of solidifying her unchallenged dominance in the Tapani sector and establishing a true Mecetti Empire, but Jedi Shadows from House Pelagia intervened. These Jedi Shadows had successfully infiltrated all levels of the Mecrosa Order. With Exar Kun's defeat, the Shadows executed their plan, and the Jedi Order defeated the Mecrosa Order in an event subsequently known as the Cleansing of the Nine Houses. Mecetti nobles, eager to avoid further disgrace, turned against Lady Brezwalt.
Brezwalt was fluent in several languages, including Basic, Bocce, High Galactic, Herglese, Malkite, Tsi, Muun and Sith. Her possessions included a lightfoil, Sith poison, and a Sith talisman.