Deep beneath the surface of Onderon's capital city of Iziz was the subterranean fortress of King Ommin. Following the defeat of Queen Amanoa during the battle of Iziz in 4000 BBY, King Ommin retreated to his fortress where he remained for the next two years, secretly planning to retake Onderon from the Jedi Knights who had assisted the Beast Rider army in overthrowing Ommin's late wife. The fortress was inadvertently discovered by Beast Rider commander Gobee and another soldier during a reconnaissance mission through Iziz's undercity. Ommin's fortress was subsequently destroyed during the second battle of the Naddist Uprising, which culminated with Ommin's death at the hands of Jedi Knight Ulic Qel-Droma.