The Altier sector was located in the Slice portion of the Expansion Region. By 0 ABY, the Altier sector bordered the Hilo and Sepan sectors Rimward, the Surron sector spinward, and the Kailion and Narvath sectors in the trailing direction. Coreward, the Altier sector also formed a four-way border with the Palamut, Tokamac, and Venzeiia sectors. The Altier sector contained the Altier, Gerhalt, Ruugia, and Trebela systems.
The Gerhalt and Trebela systems contained the terrestrial astronomical objects named Gerhalt III and Trebela, respectively, and the Altier system contained the celestial body of the same name. The Ruugia system was the origin point of the Ruugian noodles.
The Altier sector's Gerhalt system was a part of the Galactic Republic as early as 17,000 BBY.
The Gerhalt system was a part of the Galactic Republic by 17,000 BBY. From that year until 3996 BBY, a hyperlane connected the system to the Surron and Tarmidia systems; however, the hyperspace route had ceased to exist by 3960 BBY.
During the Galactic Civil War, Trebela was ruled by Governor Kraxith of the Galactic Empire. A major Rebel Alliance network operated in Trebela's capital city at that time, and it was comprised of several Rebel groups that operated independently of each other, with no group being aware of the others' activities or identities. Kraxith eventually broke up the network.
The Altier sector was introduced in the StarWars.com Online Companion to the 2009 reference book The Essential Atlas, which was written by Daniel Wallace and Jason Fry. In 2012, the Altier sector was illustrated on a map designed by Modi and published in the Online Companion feature "Essential Atlas Extra: Expansion Region."