The Prospero system was a star system in the Beta Quadrant, located on the Federation-Klingon border. It contained three inhabited planets, including Prospero Alpha.
During the Federation-Klingon War of 2256–57, Erica Ortegas was stationed near Prospero.
After the war, the Prospero system came under Starfleet jurisdiction. Ambassador Dak'Rah, a former Klingon general who defected to the Federation, was dispatched to negotiate an armistice between the three planets, which had been infighting for years. Following the successful conclusion of the talks in 2259, the USS Enterprise was assigned to transport Dak'Rah from Prospero to Starbase 12. (SNW: "Under the Cloak of War")