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Starbase 1 was a Federation starbase administered by Starfleet. It was located one hundred au from Earth, near a planetary body. In the 2250s the starbase was home to over 80,000 Federation personnel.
During the Federation-Klingon War, the starbase was attacked and occupied by the House of D'Ghor. The battle resulted in the deaths of many of the top leaders of Starfleet Command and at least three Starfleet ships were destroyed. (DIS: "The War Without, The War Within")