- You may be looking for Fifth Galaxy or Galaxy Five.
Galaxy 5 was a terrorist organisation (PROSE: Legacy) which opposed the Galactic Federation. (TV: The Monster of Peladon) According to one account, this war instead involved a galaxy called Galaxy Five. (PROSE: Doctor Who and the Monster of Peladon)
In 3935, the Federation and Galaxy 5 were at war. Galaxy 5 sent agents Azaxyr and Eckersley to take over the trisilicate mining on Peladon, which was vital for the Federation's war effort. After the failure of this mission Galaxy 5 quickly agreed to a peace treaty. (TV: The Monster of Peladon, PROSE: Legacy)
Torin Chalfont had reported from the front line on the first Galaxy 5 war. In 3999, Galaxy Five was still a terrorist threat. (PROSE: Placebo Effect)
According to the Celestial Intervention Agency, Galaxy 5 was among those who allied with the Daleks in their ill-fated attack on Earth in 4000. (PROSE: A Sourcebook for Field Agents)