Starbase 5 was a Federation facility constructed in the early 22nd century, and was originally in service to the United Earth Space Probe Agency.
In the late 2140s, a major conference regarding the future of human spaceflight was held at the base. At the conference, Dr. Milton Kornheiser stated that warp factor 4 would be the fastest speed that any warp capable vessel would be able to achieve. (ST reference: Spaceflight Chronology)
Commander Samir al-Halak traveled to Starbase 5 in 2336 on his way to Farius Prime, rather than making a planned trip to Betazed to meet with his lover, Anisar Batra. Batra eventually tracked Halak to the starbase. (TLE novel: Well of Souls)