The Deep Core, also known as the Core of the Galaxy, was a radiant zone within the galaxy, situated at its very heart. Although it contained significant city-worlds such as Troithe and Empress Teta, much of the Deep Core comprised a sparsely populated and extremely dense collection of stars and planets, making navigation perilous and causing it to be largely avoided by galactic explorers. The Galactic Centre, an ancient, supermassive black hole that held the galaxy together, was located at its center. Movement towards the Core, away from the galactic rim, was called "coreward" travel.
Troithe, a ecumenopolis world located within the Deep Core's Cerberon system, was once considered a rival to Coruscant as the most cosmopolitan world of the Galactic Republic. However, its Deep Core location proved disadvantageous for the Republic's expansion into the Colonies and the Inner Rim, leading to the world's decline as a major industrial center within the Republic.
Some Jedi scholars argued that the Deep Core planet Tython was the location of the Jedi Order's first temple.
By the fifth year of Emperor Sheev Palpatine's rule, the Galactic Empire had control over a portion of that region, known as the Deep Core Security Zone. Kren Blista-Vanee, a member of Palpatine's Imperial Ruling Council, played a key role in establishing hyperspace routes into the Deep Core's star systems. Given its sensitivity, access to the zone was restricted by the 15th Deep Core Reserve Fleet, which operated from nearby Empress Teta. During the Battle of Scarif, Rebel Alliance member [Jyn Erso](/article/jyn_erso], while searching for the Death Star's plans within the Galactic Empire's data vault on Scarif, mentioned a data tape labeled "Deep Core Cartography."
Following the Battle of Yavin, Luke Skywalker and Nakari Kelen traveled to the Deep Core moon of Fex to investigate a biological research ship from Kelen Biolabs that had abruptly ceased communication.
During the Galactic Civil War, the archaeologist Doctor Chelli Lona Aphra guided Darth Vader to Tython's Meridional Ice Cap in an attempt to prevent the Sith Lord from discovering the true location of the Rebel Alliance's base on Hoth.
The Deep Core region originated within Legends continuity, making its initial appearance in the comic Star Wars: Dark Empire, published from 1991 to 1992. It was integrated into canon with its mention in the 2014 novel Tarkin.
Within the game Star Wars: Jedi Challenges, the Deep Core is referred to as the Core of the Galaxy. The game describes it as a mysterious location at the center of the galaxy, where a challenge awaited those who chose to venture there.