- "Revan says we must take Dxun. Our wing of military droid carriers are to fly in low and drop our payloads onto the Jungle moon. Once the droids hit dirt side, they'll seek out the Mandalorian's base and pave the way for our ground troops – and the Jedi. We're expecting heavy resistance, and if the droids can't take out the anti-air turrets, this is going to be one short mission. But we cannot fail… If we do, the Republic is lost."
- ―An excerpt from the journal of a dead Republic pilot found by Meetra Surik in 3951 BBY
A massive battle on Dxun was one of the last battles of the Mandalorian Wars prior to the final confrontation between Republic and Mandalorian forces at Malachor V. The siege took place at a critical stage of the conflict and many of those who fought for the Republic believed it would determine the ultimate outcome of the war.
In the years leading up to the battle, the Mandalorian Neo-Crusaders had seen their vast territorial gains relentlessly rolled back by the Republic forces commanded by the Jedi Knight Revan. The tide of the war had turned in favor of the Republic, yet the Mandalorian fastness in the Japrael system remained intact. Before the Republic could bring the fight to the Mandalorians along the Outer Rim, their enemies' Inner Rim headquarters on Dxun had to be taken.
Revan ordered his forces to launch a large-scale assault on the Mandalorian-held world, an attack that would prove to be very costly for the Republic. The Mandalorians were deeply entrenched after decades of fortifying the moon. They were well defended by hidden minefields, traps, anti-air turrets, and the ferocious beasts of the jungle itself. As a result, the battle was one of the bloodiest in the entire war. Once it was over, the bodies of Republic soldiers and the hulks of fallen spacecraft littered the jungle floor. According to the Mandalorians, the Republic "lost many of their forces taking Dxun. For every Mandalorian soldier who fell, the Republic paid with ten of theirs."
Jedi General Meetra Surik, who would come to be known as the Jedi Exile, took part in the battle. Revan's battle plan called for hundreds of small-unit feints aimed at probing the Mandalorian line for exploitable weaknesses. Trusting in her commander's complex plan, Surik carried out her orders even though her command was scattered and had been depleted to a quarter of its full strength. The majority of her remaining soldiers were lost during a desperate charge across a minefield as they attempted to strike at the Mandalorian emplacements.
The Mandalorians refused to give ground and it took the Republic months of continuous, bloody assaults to dig them out of their fortifications. Late in the battle, Mandalore the Ultimate realized that the Republic would carry the day and he ordered his forces to abandon their headquarters. When the Republic military finally attacked the fortress, its walls were manned only by a few volunteers who had been allowed to stay and fight. In the end, Revan's forces were victorious. They retook Onderon and its companion moon Dxun, events which would set the stage for the next phase of the war.
According to Canderous Ordo "in the last months before Dxun fell, the old Mandalore knew that Revan and the Republic were gaining the upper hand." He ordered the best Mandalorian engineers "to hide caches of weapons and munitions throughout the moon, safely away from enemy hands." The Republic later attempted to search out and open these caches, but their efforts were stymied by the traps and other surprises that Mandalore's men had left behind. A decade later these weapons and supply caches would become invaluable to the Mandalorians serving Canderous—who had become the new Mandalore.
- Star Wars: Knights of the Old Republic II: The Sith Lords (First mentioned)