Foerost was a Core planet on the Koros Trunk Line between Kuar and Kaikielius. It was orbited by the Foerost Shipyards, which was one of the Republic's largest and oldest shipyards. The shipyards' engineers removed raw materials from the planet and transported them to the shipyards in high orbit.
In 3996 BBY, during the Great Sith War, a combined Krath/Mandalorian fleet stole 300 Galactic Republic warships from the shipyards for use in an assault on Coruscant. In 3959 BBY, Sith Lords Revan and Darth Malak stole a major Republic fleet from the shipyards, triggering the Jedi Civil War. In 522 BBY, the shipyards were purchased from the Republic by the Techno Union.
In 22 BBY, the Techno Union secretly tightened the security of the shipyards, in preparation for the Clone Wars. Later during that conflict, the system was blockaded by the Republic. In 20 BBY, the Techno Union broke the Republic blockade through the use of a fleet of Bulwark Mark I battlecruisers, setting off the epic Battle of Foerost. This fleet ravaged Sector Zero until it was stopped by a fleet of Victory-class Star Destroyers, the Victory Fleet.
- Tales of the Jedi: The Sith War 1: Edge of the Whirlwind (First appearance)
- Tales of the Jedi: The Sith War 2: The Battle of Coruscant
- Knights of the Old Republic 49: Demon, Part 3 (Mentioned only)
- CIS Shadowfeed Dispatch 14:7:01 Edition (Mentioned only)
- "Straight from the Horse's Mouth: A Guide to the Star Wars: Tales of the Jedi Universe, Part 2"—Star Wars Insider 27
- "Le facteur X"—Casus Belli 115
- The New Essential Chronology
- Knights of the Old Republic Campaign Guide
- The Essential Atlas
- The Essential Guide to Warfare