The galaxy was one of the billions of galaxies that existed in the universe. This galaxy was the setting of the histories of the Galactic Republic, the Galactic Civil War, the Yuuzhan Vong War, the Jedi and the Sith.
According to some sources, the galaxy was 120,000 light years across, or 37,000 parsecs (a parsec is 3.258 light years), and approximately 13 billion years old. A black hole existed at the center of the galaxy. The galaxy was orbited by seven satellite galaxies: Companion Aurek (also known as the Rishi Maze), Firefist, and Companions Cresh through Grek. However, most of the Companions were described as having ancient, metal-poor stars and not much life. There was also a hyperspace disturbance beyond the edge of the galaxy that prevented hyperspace routes outside the disk. The galaxy had nearly two hundred globular clusters.
While there was a hyperspace disturbance outside of the galaxy, hyperspace made it possible within the galaxy to have an enormous, and diverse, civilization. There were approximately 400 billion stars, and around 180 billion of these had planets that could support life. Ten percent of those planets developed life, while sentient life developed in 1/1,000 of those (about 20 million). Factoring in output of heat and light for advanced civilizations to form, there were 7.1 billion truly habitable stars, and 3.2 billion habitable star systems, with only 69 million systems meeting the requirements for Imperial representation, and 1.75 million planets considered full member worlds. In total, the galaxy was populated by approximately 100 quadrillion different life forms.
The galaxy was divided into ten main regions. They are listed here in ascending order of distance from the core to the fringe. These regions were further divided into various sectors, systems, planets and possibly moons.
At the very heart of the galaxy, the Deep Core (also known as the Core Systems) was a region that spanned seven thousand light years, and contained roughly 30 billion stars.3 Due to the gravitational pull of the vast number of stars, as well as a massive black hole at the center), local space-time was severely warped, making hyperspace travel difficult at best. The region was thought to be almost inaccessible until Emperor Palpatine found several safe hyperlanes into the region. The area remained an Imperial stronghold almost twenty years after the Battle of Endor.
An ancient region bordering the outlying areas of the Deep Core, the Core Worlds were some of the most prestigious, well-developed, well-known, and heavily populated planets in the galaxy. The Galactic Republic and subsequently all galaxywide governments were born in the Core Worlds and spread out over the galaxy. During both the time of the Republic and Empire, Coruscant, a major core world, was the Galactic Capital. The Humans were supposed to have originated from this region.
The Colonies was the name given to a region of the galaxy between the Core Worlds and the Inner Rim. It was among the first areas outside the Core to be colonized, and the worlds here were typically heavily populated, industrialized, and cultured.
During its reign, the Galactic Empire was very forceful in controlling the Colonies, and as a result, the New Republic gained support quickly there.
The Inner Rim was a region of the galaxy between the Colonies and the Expansion Region. It was originally just called “The Rim”, as it was expected to be the farthest extent of the known galaxy for centuries, but the Expanded Rim (later renamed the Expansion Region) was opened within a hundred years of the Inner Rim.
During the reign of Palpatine, the Galactic Empire ruthlessly controlled the Inner Rim. Rather than rebel, many residents chose to flee to the Outer Rim Territories. After the Battle of Endor, the Empire, despite its unpopularity, held the Inner Rim far longer than expected; many later resented the New Republic’s sluggishness in liberating the region. Many worlds, despite joining the New Republic, were openly afraid that the government was not strong enough to maintain power. Their concerns were born following the return of Palpatine, when the Empire reclaimed most of the Inner Rim.
The Expansion Region was an experiment in corporate-controlled worlds, with powerful corporations exploiting and profiting heavily from the planets for their raw materials, metals and ores. Inhabitants were oppressed while the corporations stripped entire stellar systems of all their resources. Eventually civil unrest spread from system to system. The Galactic Republic eventually took control of the system due to mounting pressure from its denizens by limiting or evicting corporate interests. Expansion Region worlds continued to be producers of raw materials and ores. However, most natural resources were exhausted by the Imperial Period.
With fewer natural resources (and therefore a smaller population) than many neighboring regions, the Mid Rim was a territory where residents worked hard for everything they had. Several planets had built up impressive economies, and pirate raiders often hid in the relatively unexplored spaces far from major trade routes.
Outer Rim Territories
The Outer Rim Territories was the last widely settled expanse before Wild Space and the Unknown Regions. It was the birth place of the Dark Lord Revan, and was also where the Mandalorians began their crusades in the hope of provoking the Galactic Republic into war. Meetra Surik was also known to have grown up on Dantooine, which was one of the Outer Rim worlds. It was strewn with obscure worlds, and rugged, primitive frontier planets. Due to its distance from the Core, the region was home to many supporters of the Rebel Alliance. The Empire’s Grand Moff Wilhuff Tarkin was assigned the difficult task of bringing the entire Outer Rim in line.
The Tingel Arm was an exterior spiral arm of the galaxy. It contained the Corporate Sector Authority, a political entity which was partially independent of the Galactic Republic and the Galactic Empire. Under the Galactic Empire, the sector expanded from a few hundred to thirty thousand systems.
Wild Space was the frontier of galactic society, separating the known parts of the galaxy from the Unknown Regions. One of Palpatine’s last acts was to open up much of the region to more extensive exploration. Wild Space differed from the Unknown Regions in that some of Wild Space has been explored, though not extensively; the Unknown Regions remained mysterious.
The term “Unknown Regions” most commonly referred to the large, unexplored region—which some interpreted to have been outside the plane of the galactic disk—between Bakura and the Imperial Remnant, which was largely dominated by the Chiss Ascendancy. The Unknown Regions comprised only a few billion stars, out of a galactic total of 400 billion. There was a lack of reliable hyperspace routes through the region. The “Unknown Regions” designation included uncharted areas in dense nebulae, globular clusters, and the galactic halo. The Galactic Empire launched many expeditions to discover and conquer Unknown Region sectors. Past the region’s outer edge, was the hyperspace disturbance beyond the edge of the galaxy.
Various established “ways” like hyperlanes passed through the sectors. These routes were explored and established by spacers known as hyperspace explorers such as like Aitro Koornacht and Jori and Gav Daragon. Astromech droids had the responsibility of guiding spaceships through these routes.
These routes were the largest and were capable of allowing spacers to traverse the galaxy in much shorter times.
Additional routes of interest
Races and species
Life developed in 10% of the habitable planets, while sentient life developed in 1/1,000 of those (about 20 million sentient species). It was estimated that they together totaled 100 quadrillion beings.
In classical history, the dominant species were Humans. Originating from the Core Worlds, Humans were the basis of the major governments. Sentients other than Humans such as Twi’leks, Hutts and Mon Calamari were simply known as “aliens”. Aliens were also distinguished as humanoid or not.
Although not considered a race for obvious reasons, droids formed a significant part, helping and coexisting with the population. On Naboo, higher level droids were considered equal as fellow sentients.