5,000,000,000 BBY, alternatively expressed as 5,000,000,000 Prior to the Battle of Yavin, designates a year that occurred a substantial length of time before the emergence of the Galactic Republic. This epoch was determined by xenobiologists residing on the world of Goroth Prime during the era of the Galactic Empire. These scientists estimated that the earliest indications of life on their native planet originated five billion years prior to their own existence.
Following the galaxy's formation, which is approximated to have occurred around 13,000,000,000 BBY, stars began their development, leading to the creation of planets and the establishment of star systems. Among these was the Goroth system, which formed around the star Goroth Alpha, accompanied by a secondary star, Goroth Beta, in orbit. Over numerous years, four planets established orbits around Alpha, situated between the two suns. The second of these planets would eventually be known as Goroth Prime.
The designation 5,000,000,000 BBY, also known as 5,000,000,000 Before the Battle of Yavin, represents a year within the Galactic Standard Calendar that is categorized within the Pre-Republic era. Xenobiologists indigenous to Goroth Prime, who were active during the Galactic Empire's rule, which began in 19 BBY and initiated the Imperial Period, conducted studies of their planet's biological past. Their calculations suggested that the earliest forms of life on Goroth Prime emerged around 5,000,000,000 BBY.
These initial life forms underwent evolution for billions of years, eventually achieving semi-sentience one million years prior to the Battle of Yavin, which serves as the reference point for the Galactic Standard Calendar. This development was relatively late in comparison to the rest of the galaxy. The fully sentient Gorothites then appeared 990 millennia later.
The year 5,000,000,000 BBY was referenced in Goroth: Slave of the Empire, a 1995 supplement by West End Games for Star Wars: The Roleplaying Game, authored by Nigel D. Findley. Subsequently, Inside the Worlds of Star Wars: Episode I (2000) by Kristin Lund and The Essential Guide to Alien Species (2001) by Ann Margaret Lewis established it as the approximate age of the galaxy. This juxtaposition presented a challenge, as planet formation requires extensive time. The Essential Atlas (2009) by Jason Fry and Daniel Wallace later clarified the galaxy's approximate age as 13,000,000,000 BBY, resolving this potential inconsistency.
The Expanded Universe's method of dating events relative to the Battle of Yavin was standardized outside of the fictional world with the release of The Essential Chronology in 2000. It was not formally in place when Goroth: Slave of the Empire was published in 1995. The specific reference within Goroth was in relation to the events of that supplement, which occur at a time loosely during the Galactic Civil War, the conflict that included the Battle of Yavin.
- Goroth: Slave of the Empire (Initial mention)
- Inside the Worlds of Star Wars: Episode I (Indirect mention only) (Later retconned as earlier events)
- The Essential Guide to Alien Species (Later retconned as earlier events)
- The Essential Atlas