- "This battle is not the last stand. It has nothing to do with honor or a willingness to meet death. This is a feint. Fortunately, I have my suspicions about where the would-be surprise blow is coming from."
- ―Nas Choka
Prior to the battle, the Yuuzhan Vong were losing territory to the Galactic Alliance rapidly and the World Brain on Yuuzhan'tar was imperfect in its terraforming attempts. Despite having lost a third of the entire Warrior caste during the course of the invasion and his forces being stretched too thin, Supreme Overlord Shimrra ordered a massive assault on Mon Calamari, the provisional capital of the Galactic Alliance. The Galactic Alliance took advantage of this by dividing its forces and sending half to Yuuzhan'tar while the other half would defend Mon Calamari.
During the battle, Lieutenant Colonel Jaina Solo along with thousands of pilots, crewmen, and gunners fought in the space surrounding Mon Calamari. The Yuuzhan Vong armada was clustered in the form of a yammosk. Each of its tentacles contained hundreds of Yuuzhan Vong warships. The actual yammosk vessels were in the center of this formation, protected by countless warships, battleships, and coralskippers. To disrupt their staging efforts, the Galactic Alliance sent the team of Kyp Durron, Han, and Leia Organa Solo to kill a yammosk on nearby Caluula. The yammosk was used by the extragalactic aliens to coordinate their forces in combat. With the death of a yammosk, the Yuuzhan Vong forces would be scattered.
Later it was discovered that it was the biological weapon Alpha Red that had killed the yammosk, and it also destroyed much of Caluula's biosphere. In 28 ABY, Vergere had sabotaged and destroyed Alpha Red, though certain elements of the New Republic Intelligence Service had restarted the project and unleashed it on Caluula. Though Alpha Red destroyed all Yuuzhan Vong lifeforms in its path, it wasn't as efficient as planned and could also contaminate non-Yuuzhan Vong life forms. Worse, a Yuuzhan Vong vessel infected with the disease had escaped Caluula and was on the way to Yuuzhan'tar.
But the Yuuzhan Vong kept pressing their attack, even with the loss of the yammosk at Caluula. They had actually never intended to use Caluula or Toong'L as draw back areas. Admiral Traest Kre'fey was about to order a retreat, when the Yuuzhan Vong armada received word that Zonama Sekot had entered the Yuuzhan'tar system. Realizing that Yuuzhan'tar came first, Warmaster Nas Choka ordered the fleet to withdraw, thus ending the battle of Mon Calamari.
- The New Jedi Order: The Unifying Force (First appearance)
- The Official Star Wars Fact File 140 (YUU12, Do Or Die)
- The New Essential Chronology (First identified as the Defense of Mon Calamari)
- Starships of the Galaxy, Saga Edition
- The Essential Atlas
- The Essential Guide to Warfare