During the Clone Wars, the Uviuy Exen system remained loyal to the Galactic Republic and eventually became a part of the Galactic Empire. Later, Uviuy Exen was the site of several battles between the New Republic and Imperial forces.
The Uviuy Exen system was located in the Shwuy sector, a part of the Northern Dependencies portion of the Colonies. It contained the terrestrial planet Uviuy Exen. The star system lay at the intersection of two hyperlanes—the minor hyperspace route known as the Shwuy Exchange, which linked Uviuy Exen to the Dankayo system, and the Hydian Way super-hyperroute, which connected it to the Eeropha and Wakeelmui systems.
Between 25,000 BBY and 22,000 BBY, a number of early hyperlanes connected the Uviuy Exen system to the systems of Chagri, Nouane, Yabol Opa, Brentaal, Coruscant, and Palanhi; however, by 17,000 BBY, these had coalesced into a single route running from Chagri to Brentaal through Uviuy Exen. That hyperlane would eventually be known as the Corsin Run, which had been merged into the modern Hydian Way by 3694 BBY.
The Uviuy Exen system was a part of the Galactic Republic by 22,000 BBY.
Although space surrounding the Uviuy Exen system only became well-explored between 20,000 BBY and 15,000 BBY, the system had already been incorporated into the Galactic Republic by 22,000 BBY. By 17,000 BBY, Uviuy Exen had allied with the planet Alsakan in its struggle against Coruscant for the status of the Republic's capital, yet it remained in space loyal to the Republic during the Clone Wars from 22 BBY to 19 BBY.
Early in that conflict, the Uviuy Exen system lay at the intersection of territories that the First, Third, and Seventh Armies of the Republic Military were tasked with defending against the military forces of the Confederacy of Independent Systems. Shortly after the acquisition of the planet Ukio by the Commerce Guild, the Uviuy Exen system was featured on a galactic map displayed on a viewscreen at a facility run by Passel Argente, the Magistrate of the Corporate Alliance.
By 17 BBY, the Uviuy Exen system fell under the control of the Galactic Empire. The military of the New Republic defeated the forces of Imperial Warlord Zsinj at Uviuy Exen in 6 ABY as part of a drive to push Imperials up the Hydian Way, and the star system had fallen under New Republic control that same year. However, four years later, another battle was fought at Uviuy Exen when Imperials advanced from the Chagri system to the Brentaal system. The population of the Uviuy Exen system numbered between 500 million and 1 billion around 25 ABY.
Due to its strategic location on the Hydian Way and the Shwuy Exchange, on several occasions the Uviuy Exen system was passed through by transiting starships traveling along those hyperlanes. The colonization and exploration vessel Outbound Flight visited the system in 27 BBY on a shakedown cruise through the territory of the Galactic Republic. During the Outer Rim Sieges phase of the Clone Wars, Republic fleets chased Confederate forces Rimward, including along the Hydian Way through the Uviuy Exen system.
The Death Star battlestation traveled through the Uviuy Exen system on its path to Alderaan.
In 0 BBY, several vessels involved with the ongoing civil war between the Galactic Empire and the Rebel Alliance traveled through the Uviuy Exen system. First, the Imperial Star Destroyer Devastator pursued the Tantive IV, the corvette of the Rebel-aligned Senator Leia Organa, between the Outer Rim worlds of Toprawa and Tatooine. Subsequently, the Devastator, with the captive senator aboard, traveled back through Uviuy Exen to rendezvous with the Imperial Death Star battlestation in the Outer Rim's Horuz system.
Shortly after that, when Grand Moff Wilhuff Tarkin, the officer in charge of the Death Star, decided to demonstrate its offensive capabilities upon the Core Worlds planet of Alderaan, the Imperial Navy cleared the hyperlanes for the mobile station to move to its target unhindered, traveling through the Uviuy Exen system on its path. Finally, the light freighter Millennium Falcon, whose crew possessed the schematics for the Death Star and had rescued Organa from the station in the Alderaan system, raced through Uviuy Exen on its way to the Rebel base on the Outer Rim moon of Yavin 4.
The New Republic's Rogue Squadron passed through the Uviuy Exen system in 6 ABY while relocating from its base on the Colonies planet Talasea to Noquivzor, also in the Colonies. New Republic forces traveled through Uviuy Exen in 17 ABY before engaging the Imperial Remnant at Champala in the Chagri system, and again in 27 ABY prior to a confrontation with the extra-galactic Yuuzhan Vong invaders at the Colonies world of Borleias.
The Uviuy Exen system was first mentioned in "Twinkle, Twinkle Little Star, How I Wonder Where We Are," a 1990 roleplaying game source article written by Glen Allison as a supplement for West End Games' Star Wars: The Roleplaying Game and published in Voyages SF 13. Since the article was released outside of the Lucas Licensing process, its canonicity within the Star Wars Legends continuity was never confirmed.
The 2009 reference book The Essential Atlas placed the Uviuy Exen system in grid square L-9. The Clone Wars: Act on Instinct, a webcomic authored by Pablo Hidalgo and released on StarWars.com over the span of the 2009–2010 second season of the Star Wars: The Clone Wars television series, subsequently featured the first appearance of the system.
- "Twinkle, Twinkle Little Star, How I Wonder Where We Are" — Voyages SF 13
- The Essential Atlas
- The Essential Guide to Warfare
- Star Wars: Edge of the Empire Core Rulebook
- The Official Star Wars Fact File Collector's Guide & Galaxy Chart
- Star Wars: Age of Rebellion Core Rulebook
- Star Wars: Force and Destiny Core Rulebook