Re-Imagined Series
The Cylon Attack (or technically, the "Second Cylon War") was the final attack by the Cylons on the Twelve Colonies of Kobol 40 years after the cessation of hostilities in the First Cylon War, the opening shot being the destruction of the Armistice Station by a basestar.
Carefully planned out by the Cylons, Humanity's defeat was ensured by Humano-Cylon agents, such as Number 6; Number 6 ensured that backdoors were placed in the Command Navigation Program, thus eliminating the Colonial's ability to resist.
As a result of the re-emergence of network technologies (see: Cylon War), the Cylons could now repeat a tactic they had previously used.
As the Colonial Fleet, under the command of Admiral Nagala onboard the Battlestar Atlantia, was ripped asunder by Cylon forces, the Cylons began deploying nuclear warfare against the Colonies. Out of billions of humans, only 50,000 survived and escaped their Cylon enemies under the leadership of the battlestar Galactica (Mini-Series) or another surviving battlestar, while a resistance movement was formed on Caprica. Also, there were other survivors that didn't make the rendezvous at Ragnar in time such as the Battlestar Pegasus, under the command of Admiral Nelena Cain could rescue them.
Original Series
- Additional information is available on the Thousand Yahren War.
The Cylon Attack was a sneak attack, similar to Pearl Harbor. After 1000 yahrens of war, the Humans vied for peace with Lord Baltar acting as diplomat. (see: Cimtar Peace Accord) The peace was to become official at Cimtar, a moon believed to be neutral territory. Instead of peace, the Cylons launched their largest onslaught ever against the Colonials.
The Cylons began a two-pronged attack:
First Prong: Elimination of the Battlestars at Cimtar
- Additional information is available on the Battle of Cimtar (TOS).
The Cylons used Cimtar as a launch platform for fighter groups, supported by Cylon tankers for fuel operations. Using their Raiders, the Cylons attacked the battlestars there. All battlestars, save the already-prepared Galactica, were destroyed; the Cylons were thwarted from destroying the entire human presence there. Leaving the survivors and Viper pilots of that battle, the Galactica headed towards the Twelve Colonies in a vain effort to protect their homeworlds.
Second Prong: The Attack on the Colonies
Cylon basestars snuck by Colonial defenses, allowing an undefended attack on the Colonies. The home planets were bombed and the Cylons exterminated all humans that survived, save those who were fortunate enough to escape and flee the Colonies to join the Fleet Commander Adama assembled.