Starbase 12 was a Federation starbase administered by Starfleet. It was located on a planet in the Gamma 400 star system, in Sector 25712, in the Alpha Quadrant. It was located close to the planets Achrady VII, Ceti Alpha V, Gemaris V, Mab-Bu VI, Pollux IV, and Risa. One function of the starbase was as a patrol base for starships patrolling the Romulan Neutral Zone. (TOS: "Space Seed", "Who Mourns for Adonais?"; TNG: "Captain's Holiday", "Power Play", "Aquiel")
In 2257, during the first Federation-Klingon War, on or about stardate 4851.5, this starbase, together with Starbase 19 and Starbase 22, was a target of a trio of devastating assaults by the Klingons, which resulted in the destruction of one-third of Starfleet's ships. The base was later occupied by the Klingons. (DIS: "The War Without, The War Within")
Later that year, after the USS Enterprise had been stopped by an unknown force, Captain Kirk ordered Lieutenant Nyota Uhura to relay the position and circumstances of the starship to Starbase 12. (TOS: "Who Mourns for Adonais?")
In 2364, the starbase was inexplicably evacuated for two days. Starfleet Command gave no explanation for this action. Captains Walker Keel, Rixx, and Tryla Scott saw this as further evidence of a conspiracy within Starfleet. (TNG: "Conspiracy")
In 2369, Starbase 12 sent a message on Starfleet Commnet One via an encoded beta channel. This base was named on the chart "Sector Ipai Relay Log – Relay Message Flow 1293" in Relay Station 47 Ops. (TNG: "Aquiel", production art)
Later that year, when Lieutenant Aquiel Uhnari and Klingon Commander Morag were believed to be coalescent organisms, the USS Enterprise-D would have ferried these two to a secure medical facility on Starbase 12. (TNG: "Aquiel" okudagram)
|Battles of the Federation-Klingon War (2256-57)|
|2256: Battle of the Binary Stars • Attack on Corvan II • Battle at Pahvo|
|2257: Scorching of Kelfour VI • Attack on Starbase 22 • Attack on Starbase 12 • Attack on Starbase 19 • Attack on Nivalla • Attack on Septra • Attack on Iridin • Capture of Starbase 1|
According to Who's Who in Star Trek 2, the Starbase was established to investigate unexplained phenomena in the Gamma 400 star system. These phenomena were later discovered to have been the work of Apollo.
Starbase 12 was also featured in the video game Star Trek: Bridge Commander and the novel Ship of the Line, in which the USS Bozeman protected Starbase 12, which was the building site of the USS Enterprise-E. The starbase was also mentioned in Star Trek: Elite Force II.