The Quarren species evolved in the low-pressure depths of Dac's oceans. Here, they mined the mineral-rich sea floor. They shared the depths of the planet's ocean with the Whaladons, the Moappa, and the Knowledge Bank. Circa 4500 BBY, the Quarren met the Mon Calamari, who lived in the shallow parts of the ocean, for the first time. However, rather than meeting in friendship, the Quarren were suspicious of the Mon Calamari and attacked them. This instigated a long war between the Quarren and the Mon Calamari. However, the Mon Calamari, though less aggressive by nature, had a superior level of technology, and won the war. The Mon Calamari, however, did not want to risk further wars, which they thought would only lead to the extinction of the Quarren.
While the Quarren recovered from the previous war, the Mon Calamari prepared for a daring cultural experiment. In order to prevent future wars, the Mon Calamari took hundreds of young Quarren captive, and taught them the ways of Mon Calamari civilization, teaching them the arts, sciences, and ethics. Once they had fully educated the Quarren, the Mon Calamari released them back to their homes. The elder generations of the Quarren distrusted the younger Quarren, and viewed them as brain-washed usurpers. The Quarren youth, on the other hand, viewed their elders as uneducated barbarians. However, the youth eventually grew up and assumed control of Quarren society, and peace between the Quarren and the Mon Calamari continued for centuries, though it was sometimes a tense relationship as followup generations of Quarren slowly began to sink back into their traditional values.
- Star Wars: The Old Republic (Codex entry) (First identified as Quarren–Mon Calamari War)
- Death in the Undercity (Mentioned only)
- (Reprint) (Mentioned only)
- Legacy of the Force: Sacrifice (Indirect mention only)