Destruction of the Twelve Colonies

The Destruction of the Twelve Colonies is a fictitious interstellar holocaust first depicted in the 1978 motion picture Battlestar Galactica, which set the stage for the subsequent television series. It is also the main premise for the 2003 miniseries re-imagining, which also spawned a television series.

Battlestar Galactica (1978)
In the 148-minute pilot film, it is established that at the end of the Thousand Yahren War, the Cylon Alliance sue for peace through Colonial representative Count Baltar with the Twelve Colonies of Man. Humanity lived on twelve colony worlds in a distant star system. They fought a thousand-year war with the Cylons, warrior robots created by a reptilian race which expired long ago, presumably destroyed by their own creations. Having never been commanded to cease fire, these warrior robots waged war against the colonials. The Colonials send a fleet of five warships known as Battlestars, to rendezvous with their archenemies, and to escort the Quorum of the Twelve (the Colonial governing body) and the President to sign the treaty. However, the peace treaty is a deception, and a betrayal of humanity by the Baltar character. Baltar also convinces the President to keep the fleet off alert status for fear of an incident with the Cylon delegation, even going so far as to characterize a wall of approaching fighters as "possibly a Cylon welcoming committee." The plan works, and the Battlestars are caught by surprise with all but one destroyed in the ensuing space battle. The Battlestar Galactica survives only because its commander (Adama) is suspicious of the Cylons, and had the foresight to put his ship on alert, and his fighters ready to launch on the pretense of a battlestations drill.

As the story progresses, Adama learns from his fighter patrol that the Cylon fighters are supported by tankers, not the Cylon baseships that normally carry them. Rightly suspecting a feint, the Galactica races to defend the Colonies, but is too late to stop their destruction. The Cylon forces are portrayed as attacking the Colonies and destroying them utterly, first via fighter attack, and then by Cylon troops deployed to the surface, as depicted on the colony of Caprica.

The story of the Colonies' destruction ends as survivors heed Adama's call, and those who can flee in whatever ships will carry them, and join the Galactica in "fleeing the Cylon tyranny."

Prelude
The Colonial fleet dispatched to escort the Quorum consisted of the President's Battlestar, Atlantia, and four others, the Galactica, Pacifica, Acropolis, and Triton (the opening movie's novelization lists another, the Solaria). Each Battlestar has a complement of 150 Viper fighters. The war with the Cylons had lasted 1,000 yahrens (years), and in that time both sides, human Colonials and Cylons, suffered heavy losses with no end in sight. The surviving Colonial Battlestar warships are under the command of the President of the Twelve Colonies (Adar), who, while on the Colonial flagship Atlantia, takes several precautions so that the fleet would be perceived as non-aggressive as possible during the peace envoy attempts. No fighter squadrons from any ship are launched, and the ships travel under the loosest of precautions. No communications are received from the Cylons while the fleet is in transit. Commander Adama of the Galactica suspects that the Cylons are up to something, and informs the President of his concerns, but the President states that it was the Cylons who sued for peace through Count Baltar, and tries to allay Adama's fears.

Cimtar
A Viper probe led by Captain Apollo and his brother, Lieutenant Zac of the Galactica ' s Blue Squadron, is sent out to patrol the flanks of the fleet. Near the moon Cimtar, a small planetoid inside a dense field of interstellar gas, they find their sensors are being jammed, but they visually spot two Cylon tankers apparently using the moon as cover. This arouses their suspicions, and they continue to investigate further. Deeper in the cloud, they find roughly 1,000 Cylon Raiders, without any Cylon Basestars. They are soon spotted, and with long-range communications impossible, Apollo decides they must return to the fleet as quickly as possible to warn it of an impending attack. During a skirmish with a Cylon patrol pursuing them, Zac's Viper is damaged, and he begins to lag behind Apollo, with only two of three Viper turbo-engines working. Yet, Zac insists that his brother continue to race back to the fleet as quickly as he can.

Meanwhile, on the Battlestar Galactica, long-range sensors begin to detect that the patrol is encountering trouble. When Commander Adama informs the President and requests permission to launch fighters, Baltar uses his influence to lull President Adar into a false sense of security. Adama had always believed that the peace conference was a Cylon trap, and orders all of the Galactica's Viper pilots to go on full alert (which he disguises as a battlestations drill). Adama has his pilots waiting in their fighters in the launch tubes, and ready to launch on a moment's notice. Later, when a wall of fighter-craft is detected rapidly approaching the fleet at attack speed, Baltar again fools the President into thinking it is a welcoming committee, and again refuses to allow Adama to order a scramble. However, all doubt of hostile intent is removed when it becomes obvious that the fighter preceding the wall, Zac's Viper, is being fired upon, and it is destroyed short of the fleet. At this revelation, Baltar immediately disappears, leaving the President in stunned confusion while Adama orders his Vipers to launch.

The battle
The Cylon fighters descend on the fleet from their left flank. Their attacks are effective, knocking out virtually all of the battlestars' ability to launch a fighter screen. The Galactica is an exception; she manages to launch nearly all of her fighters. During the battle, the remaining battlestars only succeeded in limited Viper launches. After the battle, the Galactica recovers 67 Vipers, including 42 from other battlestars, which are added to her own fighter wing.

The destruction of the Atlantia
The first target of the Cylon fighter horde is the flagship Atlantia, the President's ship, and the central command base for the fleet. Waves of fighters began a merciless assault, including suicide runs into the hangar bays, and direct hits on the bridge. The battlestar succumbs to the constant attacks, and explodes in a massive fireball.

The flight of the Galactica
Commander Adama, concerned by the lack of basestars, decides to leave the fleet and retreat to Caprica in order to mount a defence against further possible attacks. He abandons his fighter screen, which continues to fight Cylon fighters until the last three battlestars in the fleet are destroyed. The Vipers then fight their way to the Colonies, only to find the Galactica as being the last surviving battlestar.

Assault on the Colonies
While the Colonial fleet is engaged with the Raider horde, the Imperious Leader attacks the Twelve Colonies with three basestars. The attack begins with strafing runs by fighters on planetary defences and civilian targets, followed up by assaults by basestars deep within each planet's atmosphere. Cylon Centurions disembark and begin rounding up surviving humans for extermination. However, the small task force assigned to subjugate the Colonies fails to prevent approximately 220 civilian ships from escaping various unoccupied spaceports.

Aftermath
With the great majority of humanity destroyed, Commander Adama decides to use the Galactica to protect the small civilian fleet and escort them out of the combat zone, into safety. He announces a decision to lead the fleet to Earth, a mythical Thirteenth Tribe of humans lost to history. Unfortunately for the fleet, they are unable to properly refuel during their escape, and food supplies become heavily contaminated by radiation. So they are forced to set course for the planet Carillon, which has a substantial tylium mining operation, past the stellar Nova of Madagon. In a bold move, the fleet follows Captain Apollo's proposal of crossing a heavily-mined section of space as a shortcut, which is cleared beforehand by Captain Apollo himself and two of his closest friends, fellow Colonial warriors Lt. Starbuck and Lt. Boomer.

The Planet Carillon's surprisingly abundant fuel, food, and recreational facilities turn out to be a trap arranged by the Cylons and their insectoid Ovion allies, from which the refugee fleet barely manages to escape and elude pursuit &mdash; destroying both Carillon and the Imperious Leader's Basestar.

Baltar is brought in chains before the Cylon Imperious Leader. He is enraged that the Cylons reneged on the deal they had made with him about sparing his colony from destruction, and allowing Baltar to install himself as dictator. The Imperious Leader explains to Baltar that he has missed the entire point of the war. ALL humans must be destroyed. He thanks Baltar for his assistance in wiping out most of the human race, and, in the feature film, the Imperious Leader has Baltar decapitated on the spot by a Centurion. In this same scene during the TV series, the scene was slightly reshot and dialogue changed so that the new Imperious Leader explains that his predecessor had been programmed at a time when the Cylon Empire was far less tolerant of humans, but now that the Cylon Empire is omnipotent, they can afford to be more generous in their attitude towards such races. He spares Baltar's life, and places a Basestar entirely under Baltar's command. Baltar is then instructed by the Imperious Leader to "serve your people," and explain to them the change in Cylon policy dealing with humans. Baltar is then introduced by the Imperious Leader to his second in command, the IL Series Cylon, Lucifer.

The Reimagined Series (2003)
During the First Cylon War, the mechanical Cylons and Humans fought to a draw. An armistice was signed and the two sides drew a border between Colonial (Human) space and Cylon space. The Cylons withdrew into their own territory to form their own society, and generally avoided any contact with Humans for the next four decades. At the edge of Human space, an Armistice Station was built to allow Humans and Cylons to meet for diplomatic relations. Each year the Humans sent an officer; the Cylons sent no one—until 40 years after the war ended, when the Cylons suddenly reappeared at Armistice Station with no warning. But now they no longer resembled machines; instead they looked exactly like ordinary Humans. The Cylons destroyed the Armistice Station, thus beginning their final assault on the Twelve Colonies and Humanity.

After destroying the Armistice Station, the Cylons launched a sneak attack against the entire Colonial fleet. Taking advantage of their immense knowledge of advanced technology, the Cylons exploited a backdoor in the Colonial military's software written into Dr. Gaius Baltar's programs by Number Six, a Cylon working undercover who had become Baltar's lover, and who deliberately used him to find weaknesses in the Colonial defense systems he had designed.

Using the knowledge they had gained from the unwitting Baltar, the Cylons were able to override the sophisticated computer systems on each battlestar and viper fighter in the fleet and shut them down, thus rendering the ships defenseless. Within a few hours virtually the entire Colonial fleet had been destroyed. Despite President Adar's "unconditional surrender" of the Twelve Colonies, the Cylons did not respond, and detonated nuclear bombs on each of the planets. Casualties were extreme, and within a few hours, over 50 billion humans were dead. Within 24 hours after their initial attack, only the battlestars Galactica and Pegasus had survived, although they would not learn of each other's existence for some time. The Cylons, sometime after, occupied the Twelve Colonies. The nuclear attack did irreversible damage to the planets themselves: the nukes spread out so much radiation and did so much damage that the planets were going to go into nuclear winter according to Gaius Baltar. Caprica was shown to be clearly changing just days after the attack, and any survivors needed a supply of anti-radiation medication. The once blue-green world's sky turned noticeably orange, with the trees and vegetation slowly dying from radiation. Even though the Cylons ultimately abandoned the Colonies, the humans couldn't return to their homeworlds, as they were now devastated nuclear wastelands and were now uninhabitable for a very long time (as of the present day, some 150,000 years and counting).

The Plan shows exactly what happened: after preparing a massive fleet at The Colony (Cylon base that was basically the Cylon home world and site of the final battle between Galactica and the Cylons), the Cylons jumped their fleet into the orbits of the Twelve Colonies. Three battlestars in orbit of Caprica detected them, but one of the Hybrids hacked into the Defense Mainframe using the CNP backdoor and shut it down so the people on the ground couldn't detect them and defend against them. Raiders used the CNP weakness to disable the battlestars in orbit and their fighters and then launched massive pods containing multiple (at least a dozen) nuclear missiles each at each of the Colonies. Once the pods reached a certain height, they broke open and the nuclear missiles spread out and struck their various targets, nuking the Colonies. The Cavils hoped that the Final Five would have learned their lesson about humanity, be killed in the nuclear destruction and download into new bodies on board a Resurrection Ship, but each survived the attack with Cavil even helping Ellen out as he felt she hadn't learned her lesson and needed to live among humans for longer to learn it.

Battle of Ragnar
Following the destruction of Admiral Nagala's flagship, the Battlestar Atlantia, Commander William Adama of the Battlestar Galactica ordered the remnants of the fleet to regroup at Ragnar Anchorage for a counterattack; however, with nearly the entire Colonial military fleet destroyed, it was a civilian convoy led by newly-sworn-in Colonial President Laura Roslin that responded to the orders. Facing limited options, Commander Adama chose to have the Galactica defend the convoy while each ship jumped into deep space, away from the destroyed colonies. The Galactica managed to hold off two Cylon basestars as ship after ship executed faster-than-light jumps to a safe location. When the civilian ships had jumped, the Galactica then joined them. Nevertheless, less than 50,000 Humans - out of 50 billion - had survived the holocaust. Galactica and its fleet of refugees would later find that they were not the sole survivors. At least one other battlestar, the aforementioned Pegasus, had also escaped destruction. Lt. Karl "Helo" Agathon and Lt. Kara "Starbuck" Thrace would also learn that some humans had managed to survive the Cylon attack on Caprica. While this implies that at least some humans left behind by Galactica may have survived the Cylon attack and occupation of the Twelve Colonies, it is unknown if any did.

Aftermath
After the fight at Ragnar, the fleet jumped past the Red Line and into uncharted space to find a new home. Unknown to the new Fleet, they ended up with thirteen Cylons within it: the Final Five, the Cavil responsible for the destruction of the Colonies and the war that followed, two Sixes, a Doral, a Leoben, a Three, a Simon and a Sharon who was a sleeper agent on Galactica. A year later, the human fleet would link up with another survivor of the attack, the Battlestar Pegasus. Eventually the survivors discovered a habitable planet they named New Caprica and were able to settle on it for a year before being invaded by the Cylons and captured. The fleet was able to escape but not without thousands of casualties and the loss of Battlestar Pegasus under command of Commander Lee Adama.

According to Saul Tigh in Battlestar Galactica: The Resistance, twenty billion people died in the attack of the Twelve Colonies; in "A Disquiet Follows My Soul", both Kara Thrace and Felix Gaeta put the number at fifty billion.

After five years of searching, the Colonials found a new world and named it Earth. Just before Earth was found, Galactica faced the Cylons in a final climactic battle and destroyed them forever. All that were left was a group of rebel Cylons that had allied with the human fleet and settled with them, while its surviving, remnant mechanical counterparts, having finally been freed by the humans and rebel Cylons to "find their own destiny", would eventually leave the galaxy in peace, never to return.