The rapid expansion of the known galaxy by the Galactic Republic had nearly ceased with the outbreak of the First Alsakan Conflict in 17,000 BBY. This conflict marked the beginning of the Indecta Era for the Republic, but exploration eventually resumed. New sentient species were being encountered on the rimward frontier of known space. The Republic had also been changing culturally, with the establishment of the Celebratus Archive on Obroa-skai in 16,782 BBY and the creation of the first proto-lightsabers by the Jedi in the years leading up to 15,500 BBY.
In 15,500 BBY, Republic scouts exploring the Outer Rim traversed near the planet Murkhana. There, they encountered the Duinuogwuin, fifty meter–long "Star Dragons" that had the ability to travel through the vacuum of space and expel atomic fire from their mouths. The first encounter was disastrous, as the scouts were stricken with fear. Acting in haste, they retreated to Coruscant. The "Star Dragons" misinterpreted the fear, and hundreds followed in pursuit. Reaching the Republic capital-world, the Duinuogwuin attacked the planet and devastated the cityscape. However, the Republic's Supreme Chancellor Fillorean was able to open negotiations with the Duinuogwuin philosopher Borz'Mat'oh, brokering peace. As part of the deal, the two established the University of Coruscant.
The Duinuogwuin became one of many species that either came in contact or became incorporated into the galactic community during the Indecta Era. The peace brokered by Fillorean and Borz'Mat'oh lasted between the Republic and the Duinuogwuin, and some of them even became Jedi. One such Star Dragon, named Willm Lywin, established the Teyan Praxeum on Teya IV in 4600 BBY. On the University of Coruscant's main campus, statues of both Fillorean and Borz'Mat'oh were erected, and the university itself remained for thousands of years.
- Duinuogwuin Contention, which included the attack on Coruscant.
- The founding of the University of Coruscant.
Although the year itself was not explicitly mentioned in Coruscant and the Core Worlds, the 2003 Wizards of the Coast roleplaying game supplement first introduced the Duinuogwuin Contention into Star Wars canon. The date was first provided in the 2005 publication The New Essential Chronology, wherein further details of the conflict were mentioned. 15,500 BBY later received mention in Jedi vs. Sith: The Essential Guide to the Force and The Essential Atlas.
- Coruscant and the Core Worlds
- The New Essential Chronology
- Jedi vs. Sith: The Essential Guide to the Force
- The Essential Atlas