Trekipedia

Starbase 10

A space station located near Gamma Hydra IV, Starbase 10’s most important duty was to monitor the activities of the Romulan Empire near the Neutral Zone.^[3] The original strategic base defending the Neutral Zone against Romulan incursion, Starbase 10 was screened and supported by the critical Gamma Hydra cluster.^[4] Between its construction in the 2170s to 2266, it slowly became a scientific support base as well; following the Romulan incursions in the later 23rd century, it added a state-of-the-art medical facility in case of war.^{[3, 4]} Like Starbase 173, it remained at heightened alert status,^[4] and thus lacked the relaxed atmosphere of more secure starbases; everyone was constantly on edge, wondering just who might be an impostor working for Romulan intelligence.^[3]

Starbase 10, which was the destination of the U.S.S. Enterprise NCC-1701 after leaving Deneva in 2266,^[1] was originally slated to become the command of Commodore Stocker in 2267, but after his rash actions aboard the Enterprise disgraced him,^[2] command passed instead to Commodore Gerald Williams.^[3]