Eidolon Base was the designation employed by Marl Semtin when referring to the location on Tatooine where the starship known as the Eidolon was hidden, along with its stored weapons.
This base was situated at the edge of the Northern Dune Sea. Sate Pestage, a prominent imperial official who constantly feared being eliminated, owned the property. He was tasked with overseeing the construction of the Eidolon, an experimental strike cruiser intended to bolster the Imperial war effort. However, due to the ship's questionable condition and the advisor's pervasive paranoia, Pestage secretly commandeered the ship and concealed it, keeping it hidden from his superiors' awareness. He then continued to utilize the project's funding to establish the base and procure weapons, artwork, and other valuable assets from across the galaxy.
Pestage entrusted the safeguarding of this clandestine location to Captain Marl Semtin of the Imperial Navy. The captain's efforts proved unsuccessful when Rogue Squadron discovered the base, leading to its capture and removal from Imperial control. Subsequently, after the New Republic had cleared the base of its contents, a faction of former Imperials seized control and repurposed it as a sanctuary for Imperial sympathizers who were reluctant to relocate to the distant systems controlled by the Imperial Remnant. As time passed, the New Republic relinquished the land encompassing the base to the Imperials, and Eidolon Base evolved into a prosperous city in its own right. By 24 ABY, Arajen Turmen held the position of leader of Eidolon Base.