Thousand Year War

The Thousand Year War, or Neutronic War, pitted the two indigenous peoples of Skaro against one another. The conflict ravaged the planet with radiation, forcing the remaining combatants to live within domed cities. The war created a third race of sorts in the Mutos, who were made outcasts due to their disfigurement.

Even as the cause of the war was lost to memory, both sides remained committed to victory - only for both to be almost completely annihilated, with the Thals surviving only as small bands of peasants and their enemies devolving into the inhuman Daleks.

Participants
The War which devastated Skaro was fought between the Thals and the ancestors of the Daleks. (TV: The Daleks) The identity of the latter species was debated: most accounts identified the Thals' enemies as the Kaleds, (TV: Genesis of the Daleks, AUDIO: Davros, et alt.) but others referred to a race of humanoids already called "Daleks". (COMIC: Genesis of Evil, TV: The Daleks) The post-War Thals believed that the Daleks' forefathers and their enemies had been the Dals. (TV: The Daleks)

Causes
By the latter stages of the war, neither the Kaleds nor the Thals could remember why it had started. (AUDIO: Davros)

The First Doctor discovered evidence to suggest that the Thals had originally been the oppressors of the peaceful Dalek forebears. (TV: The Daleks) Historians speculated that the Kaleds had turned bitter, and, seeing the Thals build the Thal Dome to make their capital impregnable, had followed suit, leading to a cold war of sorts. It was, however, impossible to know for sure whether the actual first act of the War had been the Thal aggression the Kaleds feared, or a preemptive strike on the Thals by the Kaleds. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

However, a different account claimed that the Thals had inhabited the continent of Davius, far away from the humanoid Daleks' home on Dalazar, across the Ocean of Ooze, and that they had been peaceful and agreeable. The War Minister of the Daleks, Zolfian, had wished to destroy the Thals out of sheer xenophobia, a sentiment shared by some of his people but not by their leader, the pacifist Drenz.

After the discovery of large amounts of pure cobalt in the Radiation Range, the Daleks had been able to manufacture a "mighty" neutron bomb with which to intimidate, or even exterminate the Thals. When Drenz opposed the project, he was assassinated by Zolfian, who also had the great scientist Yarvelling create Dalek War Machines. (COMIC: Genesis of Evil) Events similar to this account were dismissed by human historians as distorted myths. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

Further fighting
By the time that the Fourth Doctor visited Skaro on a mission to prevent the creation of the Daleks, the Thals and Kaleds lived in two domed cities overlooking a polluted wasteland marked by discarded war machines, corpses, and minefields. The Scientific Elite, headed by Davros and his assistant Nyder, and a Military Elite hoped to create weapons that would finally bring victory. The use of nuclear, chemical and biological weapons had led to genetic mutations among both Thals and Kaleds, disparagingly referred to as Mutos. The Mutos were driven out by the Thals and the Kaleds to keep their races pure.

By this time both sides had become so desperate for soldiers that they were deploying boys in their early teens on the battlefield and the chief Kaled commander, General Ravon, was a young man in his early twenties.

An anachronistic mixture of technologies on the battlefield showed a society which had devolved rather than evolved, with combatants using energy weapons alongside rifles and machine guns and engaging in trench warfare as in Earth's early 20th century with minefields, barbed wire, and gas shells being used frequently during engagements. Their uniforms were frequently mismatched - soldiers could be seen wearing modern combat jackets made of synthetic fibre with other articles of uniform made of leather.

When the Time Lords sent him and his companions Sarah Jane and Harry to Skaro to avert the creation of the Daleks, the Fourth Doctor speculated the Kaleds and the Thals had been fighting for so long that when the war had begun they had both started out with the most modern equipment, but as the centuries passed they lost the resources and had to make do with what they had. Indeed, General Ravon, one of the commanders of the Kaled army, harshly reminded one of his underlings ammunition was valuable and could not be wasted.

In the long-range, as well as the biological and nuclear weapons already mentioned, both sides used chemical rockets. Towards the end of the war, the Thals intended to use a neutronic missile against the Kaleds. (TV: Genesis of the Daleks)

On the battlefield, mutant Handmines were used. Kanzo was pulled underground by one, while a boy Davros, having been lost on the battlefield of the War, was surrounded by them. At that point, both laser-firing biplanes and bows were used on the battlefield. (TV: The Magician's Apprentice) After an encounter with a future version of Davros, the Twelfth Doctor rescued Davros from the battlefield in order to teach him the concept of mercy. (TV: The Witch's Familiar)

Extermination of the Kaleds
Foreseeing that the only way forward for his kind was to accelerate their evolutions into the machine Daleks, Davros gave the Thals information to allow them to breach the Kaled Dome, causing massive casualties amongst Davros' own people. This provided a rationale for the Kaleds in turn to set the newly created Daleks against the Thals. At last, a Thal rocket destroyed the Kaled Dome. Thals, led by Bettan and Mutos, led by Sevrin, joined to fight against the Daleks emerging from the ruined Kaled city. The Daleks were forced back into Davros's bunker and imprisoned there for "a thousand years" by the Fourth Doctor, although their leader and oldest member vowed they would one day reemerge. (TV: Genesis of the Daleks)

Detonation of the neutron bomb
The surviving Thals saw no difference between these new machine-Daleks holed up in their ruined city and their ancient enemies, and massed forces to continue the War. Learning of this danger, the Daleks detonated a neutron bomb which instantly wiped out nearly all life on the planet Skaro, and left it so irradiated the Daleks remained confined in their city for fear of succumbing to radiation poisoning themselves. (PROSE:  The Astounding Untold History of the Greatest Enemies of the Universe)

According to another account, there never was an actual Thousand-Year War: before either side could genuinely begin fighting, a freak meteor shower had hit the factory in which the humanoid Daleks had created the neutron bomb. Detonating in the heart of the Dalek capital, the neutron bomb annihilated most life on Skaro in a single day, leaving the humanoid Daleks more or less extinct, the Thals as a scrambling band of survivors without access to higher technologies, and a new race of mutated Daleks alive on Skaro's surface to settle inside Yarvelling's War Machines, repurposed as casings. (COMIC: Genesis of Evil) According to the Thal Alydon, five hundred years later, Skaro, which Alydon described as "a great world, full of ideas and art and invention", had been destroyed in one day. (TV: "The Expedition")

Legacy
Beyond the existence of the Daleks and near-destruction of Skaro as an inhabitable world, (TV: Genesis of the Daleks, The Daleks) the War also had a much more mundane aftereffect, namely the publication of the popular Earth science fiction novel World War Skaro by the Doctor's former companion Sarah Jane Smith, (PROSE: The Roving Reporter) as, being a time-traveller, she had been privileged to witness the near-end of the Thousand Year War with the Doctor. (TV: Genesis of the Daleks)

Alternate timeline
In an alternate timeline, the war, known as the Neutron War, was caused accidentally. Though the Daleks still developed, in this timeline they became peace-loving academics. Skaro was the universal centre of civilisation, philosophy, democracy and art, visited from all over the universe. (PROSE: The Ripple Effect)

Behind the scenes

 * According to the non-narrative reference book Doctor Who: The Dalek Handbook, the war lasted from 450 AD to 1450 AD.
 * According to the second and third editions of AHistory, the war lasted from 240 BC to 760 AD, and was a separate conflict from the neutronic war, which was fought in 1763.

Rhyfel Mil Flwyddyn Tausendjähriger Krieg Guerra de los Mil Años