Fall of the Twelve Colonies

The Fall of the Twelve Colonies, also known as the Second Cylon War, was a massive Cylon campaign against Colonial space that saw the indiscriminate destruction of civilian and military targets alike with the objective of the total annihilation of mankind. The attack succeeded beyond the Cylons' most optimistic projections, but they failed to destroy humanity in a single day. (Battlestar Galactica, miniseries; Battlestar Galactica, "Downloaded")

Background#

Forty years before the Fall, the Cylon War ended in an armistice. With the arrival of the Final Five, humanoid Cylon refugees from Earth, the Colonial Cylons agreed to stop fighting. The Colonials kept control of their own space, and the two sides met only at Armistice Station, past which lay Cylon territory. (Battlestar Galactica, miniseries; Battlestar Galactica, "No Exit")

Over those forty years the Cylons changed radically. With the help of the Final Five, new humanoid Cylon models were created. The first of them, Number One, known as "John" or "Cavil," turned against the Five, killed them, boxed their memories and, once they had been resurrected, sent them into Colonial society convinced they were human. He then planned to wipe out mankind as an act of revenge against the Five, disgusted that they had created him in a limited, human-like body. Officially, the Cylon plan was presented as revenge for the original enslavement, with knowledge of the Five erased from the other Cylons' memories. (Battlestar Galactica, "No Exit")

By the time of the attack, the Colonial Fleet relied on modern, networked battlestars, and Galactica, the last of the old warships from the first war, was being decommissioned and turned into a museum. Some years earlier Adama, then commanding the battlestar Valkyrie, had sent an experimental Stealthstar across the Armistice Line to test Cylon defences, a mission he later feared had provoked the attack. Coinciding with the fleet's modernisation was the development of the Command Navigation Program, a networked system to be installed in military craft. Its architect was Dr. Gaius Baltar, working with networked computers that Adama had always refused aboard Galactica because of Cylon infiltration during the war. A Number Six, later known as Caprica Six, gained Baltar's trust and used her access to plant back doors in the program, letting the Cylons penetrate Colonial defences and shut ships down. (Battlestar Galactica, miniseries; Battlestar Galactica, "Hero")

Initial attack#

The Cylon attack force gathered at The Colony before jumping to its targets. The first shots were fired at Armistice Station, the diplomatic space station, which a Basestar destroyed. Shortly before the attack, a Number One personally met with Caprica Six to receive the program details that the Cylon forces would exploit. (Battlestar Galactica, miniseries; Battlestar Galactica: The Plan)

Over Caprica, the Colonial Fleet moved to intercept the strike force, Valkyrie among the battlestars. The battlestars and their Viper wings were quickly disabled by the hacking, allowing the Basestars to concentrate on the planet and fire nuclear missiles at densely populated areas such as Caprica City. Similar attacks fell on the other colonies. Over Scorpia the Fleet Shipyards were destroyed. Picon Fleet Headquarters was destroyed in the bombardment. Pegasus escaped the shipyards by performing a blind jump, possible only because its computer networks were down for a refit. Through the hacking, the Colonial Fleet lost thirty Battlestars, roughly a quarter of its strength, in the opening wave, and the networked Viper Mark VIIs were picked off by Raiders. President Adar offered an unconditional surrender that the Cylons ignored entirely, and Centurions landed on the ruined worlds and hunted down survivors. On screen the attack fills the two-night miniseries that opens the list of every Galactica episode. (Battlestar Galactica, miniseries; Battlestar Galactica, "Pegasus"; Battlestar Galactica: Razor; Battlestar Galactica: The Plan)

Colonial counteroffensive#

When the scale of the attack became clear, Admiral Nagala took personal command of the fleet and ordered the surviving ships to gather for a counteroffensive near Virgon. Nagala's force, flagship Atlantia among it, engaged the Cylons. The battle was a catastrophic failure, for the hack was still unknown. Atlantia was destroyed. When word of Atlantia's destruction arrived, Commander William Adama of Galactica assumed command and ordered all remaining ships to rendezvous at Ragnar Anchorage to resupply and regroup for a counterattack. Before it could leave, Galactica came under attack itself. Its museum wing of Viper Mark IIs, lacking networking, held off the Raiders, though Galactica was still damaged by a nuclear missile and Colonel Tigh vented the burning compartments near the hangar deck, killing the crew trapped inside to save the ship. (Battlestar Galactica, miniseries)

Civilian situation#

Soon after the initial attacks, the Colonial Government shut down the civilian spacelines to keep civilian ships out of the combat areas. Unprepared for long journeys, some of these ships began to lose power. Laura Roslin, the Secretary of Education, took charge aboard the government transport Colonial Heavy 798 and began rescuing stranded civilians. When word came that President Adar and most of the government were dead, Roslin, forty-third in the line of succession, was the senior surviving official and was sworn in as president, and the ship took the call sign Colonial One. Over the following hours a civilian fleet assembled, with the help of a stranded Raptor that located FTL-capable ships. Among the survivors were the Earth Cylons Tory Foster and Ellen Tigh. When a Raider located the fleet, Roslin decided that all FTL-capable ships would jump to Ragnar, leaving the sublight ships behind. (Battlestar Galactica, miniseries; Battlestar Galactica: The Plan)

Battle of Ragnar Anchorage#

During Galactica's resupply, a Number Two was found on the station. Posing as the arms dealer Leoben Conoy, his rapid deterioration from Ragnar's radiation drew the attention of Commander Adama, who realised he was a Cylon and killed him. When the civilian fleet reached Galactica, Baltar, prompted by the Six only he could see, accused civilian PR manager Aaron Doral of planting a suspicious device in the CIC. Doral was abandoned on the station and later turned out to be a Number Five, though who planted the device was never confirmed. Orders were also given to keep networking off on the ships that reached Galactica. (Battlestar Galactica, miniseries)

With no surviving Battlestars reaching Ragnar, Adama accepted that the war was lost and that fighting on would doom the refugees. The decision was made to abandon the Cyrannus star system entirely and seek a new home far from the Cylons, with Galactica protecting the convoy. Cylon Basestars were already waiting outside Ragnar, and to give the civilians time to escape Adama positioned Galactica between the refugees and the enemy. The chase didn't stop there: for days afterwards the Cylons caught up every 33 minutes, as shown in the episode "33". (Battlestar Galactica, miniseries; Battlestar Galactica, "33")

Aftermath#

Within a day of the initial attack, almost the entire human population of the Colonies had been wiped out. The Cylons began repairing the damaged cities and living in them. Surviving humans suffered the effects of radiation exposure, which limited resistance. After several weeks, the only meaningful resistance was on Caprica, surviving in the hills and protected in part by the Cylons' unwillingness to kill its leader, Samuel T. Anders, one of the Final Five. Roughly fifty thousand people escaped in refugee ships and aboard the Battlestars Galactica and Pegasus. The Cylons later abandoned the occupation of the Colonies, and both races set out to search for a new place to live. What came next, from New Caprica to Earth, runs year by year on the Battlestar Galactica timeline. (Battlestar Galactica, "33"; Battlestar Galactica, "Downloaded"; Battlestar Galactica, "Lay Down Your Burdens, Part II"; Battlestar Galactica: The Plan)