The Cylon Civil War was a genocidal conflict between two opposing factions in Cylon society.
Background[]
For several decades, Cylon society evolved under the manipulation of the Number Ones, who were based on the first prototype created by the Final Five, the survivors of the Thirteenth Tribe. In a revolution led by the Ones, Centurions were implanted with teloncephalic inhibitors to effectively rob them of sentience and reduce them to slavery. The other seven Humanoid Cylon models were reprogrammed to avoid thinking about the missing Five.
In the months following the Fall of the Twelve Colonies, the Ones' control over society was repeatedly challenged. A social revolution focused on individuality within lines led to the challenging of the war's merits, forcing in an end to hostilities with mankind. A Number One went on board the survivor ship Galactica with refugees from Caprica to give the news in person ahead of his execution along with the One who led a terrorist cell from Galactica itself. The latter One was opposed to this new way of thinking in society, and upon his execution endeavored to keep things as they were. Another crisis emerged over a year later, when a Three's hallucinations allowed her to break her programming and recognize the Final Five's faces. With it being too late to stop the other Threes accessing her memories, the Number Ones had all of them shut down, allegedly due to a malfunction they were experiencing. An emergency summit took place on whether or not to unbox the Threes, which led to tie between the Ones, Fours and Fives against the Twos, Sixes and Eights. As Cylon democracy worked on a College system, only one vote was needed to represent an entire line. This unwritten constitution was put into question when "Boomer", an Eight, expressed support for the boxing, effectively given her line two votes, resulting in a 4–3 win for continued boxing.
Conflict[]
During the Battle of the Ionian Nebula, the Cylon Raiders came into contact with Ensign Samuel T. Anders, a new recruit of Galactica and secretly one of the exiled Five. Upon becoming aware of his identity as a Humanoid Cylon, the Raiders withdrew and refused to fight the human fleet any further. The Ones responded to this proposing the emergency surgery on the Raiders, to be carried out by the Fours, which was again won 4–3. In an act of rebellion, the Twos, Sixes and Eights began illegally removing the inhibitors from Centurions, who began massacring those who supported the lobotomization upon gaining free will. The Ones, Fours and Fives responded by having their Basestars destroy the rebels in surprise attacks under a flag of peace.