During the Clone Wars, the Expansion Region world of Umbara was the site of a prolonged battle in 20 BBY between the Grand Army of the Republic and the native Umbarans, who had aligned themselves with the Confederacy of Independent Systems. Numerous clone troopers and Umbaran soldiers were killed during the fighting. The Besalisk Jedi Master Pong Krell commanded the 501st Legion during the battle and proved unpopular with his men. After Krell's treason was revealed, the trooper Dogma executed the fallen Jedi for betraying the Galactic Republic. In the aftermath of the battle, the Republic occupied Umbara.