Sienar Fleet Systems (SFS) reigned as a top-tier producer of starships, weaponry, and propulsion systems across the galaxy. They achieved peak recognition during the Galactic Empire's reign, particularly for their iconic TIE fighter series starfighters. Previously, during the Republic Era, the company was known as Republic Sienar Systems. Following the Galactic Concordance, the organization restructured into Sienar-Jaemus Fleet Systems and Sienar-Jaemus Army Systems to circumvent limitations on arms sales to the First Order.
During the Clone Wars, Sienar Fleet Systems was a major supplier of military transports and landing vehicles for the Galactic Republic. Sienar was also commissioned by the Republic Navy to develop a prototype corvette, a stealth vessel utilizing an experimental cloaking device. This device, reportedly engineered by Republic scientists, rendered the ship invisible to both sensors and visual detection. This spear-shaped stealth ship was successfully deployed by Republic forces to eliminate a Separatist dreadnought. However, the prohibitively high cost and complex maintenance of the cloaking technology prevented the Navy from ordering more of these stealth ships.
By the conclusion of the Clone Wars, the company had fallen into bankruptcy and was under the ownership of the InterGalactic Banking Clan. Following the invasion of Scipio, SFS's assets were transferred to the office of the Chancellor.
With the ascent of the Galactic Empire, Raith Sienar assumed leadership of SFS, personally spearheading the design of the Imperial TIE/ln space superiority starfighter. As a rival to Kuat Drive Yards, Sienar's rise during the Imperial era involved acquiring critical resources and engineers previously working for KDY, which ultimately led to the creation and production of the TIE fighter series. While the Sienar family amassed considerable wealth through the production of TIE fighters for the Empire, one of its members, Gracalia Vatara Sienar, defected to join the ranks of the Alliance to Restore the Republic. By the time the First Order gained prominence, SFS had evolved into Sienar-Jaemus Fleet Systems and Sienar-Jaemus Army Systems.