The Umbaran militia was the local defense force of Umbara, a shadowy world in the Ghost Nebula. The militia was comprised of the planet’s native Umbaran people, who utilized their advanced technology that had been developed on their world to defend their holdings and attack enemy forces. Aside from the soldiers who served as infantry units, the militia also made use of millicreep assassin droids, heavy hover tanks, multi-legged assault tanks, and massive and mobile heavy cannons. The Umbarans also employed air defense vehicles, including their technologically-unique starfighters and combat support ships.

During the Clone Wars, the Umbaran militia fought against the Galactic Republic in support of their world’s defection to the Confederacy of Independent Systems. Although the Grand Army of the Republic’s Jedi Generals had hoped for the combat on the world to be quickly resolved, the Umbaran militia proved to have be more resourceful and tenacious than predicted. The Umbarans inflicted heavy casualties against their enemy’s clone trooper forces, but were eventually forced to fall back towards the capital city of Umbara. After the Republic’s 501st Legion seized a key militia airbase, High Jedi General Obi-Wan Kenobi moved on the capital and usurped control from the Umbaran natives. Despite receiving covert assistance from rogue Jedi Master Pong Krell, the militia met with defeat near their captured airbase, ending the battle for Umbara.