The Gamor star system was located within the Expansion Region's Chaykin sector. It lay between the Allanteen and Milagro systems on the Corellian Run super-hyperroute, which served as a dividing line between the regions known as the Slice and the Trailing Sectors. The star system also formed one endpoint of the Gamor Run hyperlane, which connected it to the Merren system.
The area of space surrounding the Gamor system was explored between 25,000 and 20,000 BBY, although the system itself had already been under the control of the Rakatan Infinite Empire by 25,200 BBY. The Gamor system became a battleground during the Great Sith War in 3996 BBY, when, following a victory over the forces of the Sith sect in the Denon system, the Corellian fleet of the Galactic Republic traveled along the Corellian Run toward Gamor and defeated the Sith there as well. During the Jedi Civil War, fought forty years later, the system lay within the territory claimed by Darth Revan's Sith Empire.
In 22 BBY, the Gamor system fell within the borders of the Confederacy of Independent Systems, and, as part of the Clone Wars, the Republic's Sixteenth Sector Army was charged with engaging the military forces of the Confederacy in the system's vicinity. Shortly after the acquisition of the planet Ukio by the Commerce Guild during that conflict, the Gamor system was featured on a galactic map displayed on a viewscreen at a facility run by Passel Argente, the Magistrate of the Corporate Alliance. The system was located within space controlled by the Galactic Empire by 17 BBY.
The population of the Gamor system around 25 ABY was between 10 billion to 100 billion. During the early stages of the galactic conquest carried out by the extra-galactic Yuuzhan Vong species, the Yuuzhan Vong military forces passed through the Gamor system before attacking the Rhommamool and Tynna systems. The Gamor system remained under the control of those invaders by 27 ABY.
The Gamor system was first mentioned in the 2009 reference book The Essential Atlas, authored by Jason Fry and Daniel Wallace, which placed the system in grid square O-14. 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, featured the first appearance of the system.
The 2013 Core Rulebook for Fantasy Flight Games' Star Wars: Edge of the Empire roleplaying game introduced an erroneous spelling of "Gamorr" for the Gamor system, which was repeated the following year in the Core Rulebook for the Star Wars: Age of Rebellion roleplaying game. In addition, both of those books, as well as the 2015 Core Rulebook for the Star Wars: Force and Destiny roleplaying game, contained a map of the galaxy in which the placements of the Milagro and Bacrana systems had been mistakenly switched, thereby erroneously depicting the latter as the Gamor system's closest Rimward neighbor on the Corellian Run hyperlane.
- 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: The Card Game — Knowledge and Defense
- Star Wars: Age of Rebellion Core Rulebook
- Star Wars: Force and Destiny Core Rulebook