Alpha Theta VI was a remote Federation world that was home to a starbase and defended by a small fleet. The installation was commanded by Admiral Fleming.
The Borg attacked the planet after the Dominion War. While Starfleet was able to hold off the Borg for a time, their supplies were drained. Federation ships from a nearby starbase were able to fight their way past the Borg and deliver dilithium, latinum, metals, and crew to the base. In turn, the defenders were then able to drive back the Borg attackers. (ST video game: Armada II)