The Gungan Grand Army represented a substantial army and standing militia force located on the planet of Naboo, and it was made up exclusively of Gungans. Their contributions proved critical to securing victory during the conflict that arose when the Trade Federation initiated an invasion of Naboo and subjected the Naboo people to enslavement. Subsequently, the army lent its support to the Battle of Mon Cala following a request from Jedi Grand Master Yoda.
The Gungans, an amphibious species indigenous to the serene Mid Rim planet Naboo, harbored suspicions towards outsiders and maintained a standing militia, referred to as an Army. However, the army's primary role revolved around managing dangerous wildlife, and by the time of the Invasion of Naboo, the army had not been mobilized for combat for a considerable number of years.
A decade prior to the commencement of the Clone Wars between the Galactic Republic and the Confederacy of Independent Systems, the Trade Federation established a blockade surrounding Naboo, subsequently launching an invasion and occupying the planet's surface. During the battle to liberate the planet from the Federation's control, the Gungan Grand Army was mobilized by Boss Nass upon the request of Queen Amidala of the Naboo. Under the leadership of General Tobler Ceel, the Gungan Grand Army engaged in battle against the Trade Federation Droid Army on the expansive Great Grass Plains, situated 40 kilometers from the planetary capital of Theed. Their actions served as a diversion, drawing the battle droids away from the city to enable Amidala and the Royal Naboo Security Forces to infiltrate the Theed Royal Palace and apprehend Viceroy Nute Gunray. Militiagungs participating in the battle held the belief that Bombad General Jar Jar Binks, a Gungan officer, was divinely favored. Initially, the Grand Army faced defeat, but the battle droids were deactivated following Anakin Skywalker's destruction of the orbiting Droid Control Ship.
Following their triumph over the Trade Federation's Droid Army, the Gungan Grand Army marched victoriously into Theed, where they received a warm reception from the inhabitants as liberators for their role in freeing Naboo from the Trade Federation. Boss Nass and Jar Jar Binks, accompanied by the rest of the Army, were celebrated by the human civilians of Naboo as they paraded through the city. Queen Amidala presented Boss Nass with the Globe of Peace, symbolizing the commencement of amicable relations between the Gungans and humans of Naboo.
During the Clone Wars period, Jedi Grand Master Yoda reached out to Gungan Boss Lyonie of Otoh Gunga to request assistance in the Battle of Mon Cala. Binks, by this time holding the position of Senator in the Galactic Senate, successfully persuaded Lyonie to provide support to the Grand Army of the Republic. A contingent of the Grand Army was dispatched to Mon Cala aboard a Venator-class Star Destroyer. Numerous Gungans perished in combat against the AQ-series battle droids, with many more captured when Separatist leader Riff Tamson employed a Trident-class assault ship to generate a whirlpool. The captured soldiers were confined to a prison camp situated amidst Mon Cala's coral reefs. Shortly thereafter, Mon Calamari prince Lee-Char visited the camp, instructing the prisoners to await his signal before initiating an attack. Lee-Char was subsequently apprehended, brought before Tamson, and scheduled for execution. The Quarren, who had initially aligned with the Separatists but later betrayed them, liberated the members of the Grand Army. The Grand Army retaliated, with some Gungans joining Captain Ackbar in disabling a Trident assault ship. Ultimately, the Republic and Gungan forces emerged victorious in the battle, and Lee-Char was crowned king.
Later in the Clone Wars, tensions arose on Naboo due to spreading rumors alleging that the Gungans had formed an alliance with the Separatist Alliance. Boss Lyonie summoned the Grand Army to march on Theed. Amidala, now serving as Naboo's senator, and Skywalker returned to Naboo to de-escalate the situation. They encountered Binks on Lake Paonga, and the Gungan escorted them to Otoh Gunga to meet with Lyonie. Lyonie initially declined their assistance, but Skywalker discerned that Lyonie was under a form of mind control exerted by a necklace bestowed upon him by Minister Rish Loo. The Jedi utilized telekinesis to crush the necklace, freeing Lyonie from its influence. In response, Loo stabbed Lyonie as the Boss confronted him. Loo then fled Otoh Gunga and proceeded to the surface to inform the Grand Army of Lyonie's demise, urging them to march on Theed.
Despite surviving the stabbing, Lyonie remained unconscious. Skywalker, observing Binks' resemblance to Lyonie, persuaded him to impersonate the Boss in order to dissuade the Grand Army from launching the attack. Binks successfully deceived the Grand Army into believing that he was Lyonie, and Rish Loo, realizing that his plans had been thwarted, retreated deeper into the swamps aboard a Flitknot speeder. Three C-9979 landing craft landed nearby, with one deploying a tactical droid accompanied by a B2-series super battle droid escort. Binks and General Tarpals followed the tactical droid onto the landing craft, where they encountered General Grievous. Binks, still posing as Lyonie, informed the general that he would not attack Theed, which angered Grievous. Binks then relented and instructed Tarpals to prepare the troops for battle. Tarpals proceeded to contact Amidala, who proposed a strategic plan. Meanwhile, Grievous discerned Binks' deception and attempted to eliminate him. Binks managed to escape and realized that the Grand Army had successfully disabled the droid army and had gathered around Grievous. Tarpals and several other warriors engaged the general in skirmish_on_naboo. Tarpals was fatally wounded by Grievous but managed to impale the cyborg with an electropole. The distraction provided the other Gungans with sufficient time to attack Grievous with boomas and capture him.
Skywalker pursued Loo to his secret outpost, which was being utilized by Count Dooku, the head_of_state of the Confederacy of Independent Systems. Dooku eliminated Loo and then subdued and captured Skywalker. Amidala agreed to release Grievous in exchange for Skywalker, and the Grand Army delivered the general to Dooku. Subsequently, the Separatist army departed from Naboo. Queen Neeyutnee then commended Binks for his role in reuniting the Naboo and the Gungans.
In contrast to the Royal Naboo Security Forces stationed at the human city of Theed, the Gungan Grand Army relied on organic beings and limited technological advancements in combat, adopting a more defensively oriented strategy. Nevertheless, their weaponry incorporated shield and plasma technology, rendering it exceptionally formidable. The army comprised approximately 1,000 battle-ready animals, including fambaas, falumpasets, and kaadus. Fambaas frequently carried deflector shield generators capable of enveloping large contingents of Gungan troops, while falumpassets towed substantial battle wagons, and kaadus served as cavalry mounts for leaders such as Captain Roos Tarpals, who adorned his kaadu with elaborate feathers acquired as racing trophies.
Gungan soldiers were commonly armed with spears or one-armed throwing devices known as atlatl, which could launch grenade-like energy weapons referred to as boomas. Manufactured by the Otoh Gunga Defense League using exotic plasma naturally occurring in Naboo's porous crust, boomas could also be launched using spear-like cesta or falumpaset-towed catapults. The Gungan personal energy shield, which employed hydrostatic bubble technology to provide protection against blaster fire and physical weapons, was widely distributed among Gungan forces.