Poggle joined the growing secessionist movement created by Count Dooku and funded by members of the Trade Federation, Commerce Guild, and Intergalactic Banking Clan. While the larger corporate entities lobbied and gained supporters in the Republic Senate the Separatists began a massive construction operation on Geonosis creating thousands and thousands of battle droids for their new army. The management of this operation was left to Poggle, the Archduke.
Second Battle of Geonosis
After Senator Padme Amidala discovered a new series of droid factories on Geonosis the Republic launched a massive offensive to retake the planet and deny the Separatists the use of the new battle droids being produced there. Poggle and his Tactical Droid planned to use the large new army he had created to overwhelm the Republic and recapture he lost military bases. A Republic Assault led by Jedi Masters Ki-Adi-Mundi and Luminara Unduli with assistance from Anakin Skywalker, padawans Ahsoka Tano and Barriss Offee, and clone troopers Rex and Gree mounted an attack on Poggle's new factories. While Luminara and Anakin distracted Separatist forces padawans Tano and Offee were able to take a crucial super tank factory thwarting Archduke Poggle's plan to use the new tanks to win back his planet.
Later on Jedi Master Mundi succeeded in breaking through the Geonosian defenses and succeeded in capturing Poggle. The Archduke was later escorted under heavy guard to Coruscant for trial.