Dalek War Machine

The Dalek War Machine was the name given to the weapon (and what would become the first variant of Dalek drone) created by scientist Yarvelling of the original Dalek race to aid in their war with the Thals. After the explosion of a neutron bomb destroyed both sides' civilisations, the Dalek mutants retreated into the casings of the machines. After the last of the original race, Yarvelling and Zolfian, had both perished (COMIC: Genesis of Evil) the name Dalek Machine to refer to the species remained for a time (COMIC: Power Play) before simply Dalek became the commonly used term. (TV: The Daleks, COMIC: Duel of the Daleks et al.)

Eventually, as their technology improved, the Daleks modified their design beyond the Dalek War Machine created by Yarvelling such as the addition of slats to their weapons platform. (COMIC: Shadow of Humanity, The Emissaries of Jevo et al.) These new and improved Daleks more closely resembled the Mark III Travel Machines supposedly created by the Kaled scientist Davros (TV: Genesis of the Daleks) but more accurately based on designs stolen from other scientists from whom Davros stole the credit in a bid to claim leadership over the Daleks. (PROSE: War of the Daleks)

History
The first Dalek War Machine was presented by Yarvelling to minister Zolfian at a War Council meeting. The latter ordered mass production of the machines, believing them to be the perfect weapon to destroy any surviving Thals after the explosion of their neutron bomb. As the bombs were accidentally exploded prematurely, the Humanoid Dalek race mutated from the radiation and were forced into the casings of the War Machines as protection.

After two years, Yarvelling and Zolfian emerged from their bunker and discovered what their race had become. They rebuilt the war factory but both perished before they could make more machines to shield themselves from the radiation. After they died, the first Machine Dalek declared himself Emperor. (COMIC: Genesis of Evil)

Their first act under the new Emperor was to build the Dalek City and they achieved this feat in two months. As a safety precaution, the Daleks also magnetised the metallic sand surrounding the city, allowing them to pull it towards the city at will, covering it in a large dune that concealed it from unwanted visitors.

Shortly after these events, the planet was visited by a Krattorian spacecraft piloted by the slave-trader Kest. As Kest was here to mine the metallic sand, he soon uncovered the Dalek City, and the Daleks decided to take advantage of this to steal the secrets of space travel from him. Though the ship managed to escape Skaro, the Daleks were undeterred, and, in possession of its schematics, set about crafting spaceships of their own. (COMIC: Power Play)

A worker in the inventions factory, Zeg, discovered a stronger Dalekanium alloy called Metalert that would aid in their interplanetary travel. An Oquolloquox directly struck Zeg and he absorbed the sunlight and the Metalert which meant he was now resistant to immense heats and could feel some level of emotion. He challenged the Emperor and managed to survive acid, mercury and the gunstick of the feared Black Dalek but the extreme cold of liquid oxygen crushed him. (COMIC: Duel of the Daleks)

When the Doctor first encountered them, the Daleks were stranded in their city on Skaro, as their casings were powered by static electricity channeled by the metal floors of the City, preventing them from leaving it. They eventually found that the Thals had also survived what was known as the neutronic war. After discovering that they had become dependent on the background radiation to the point of the anti-radiation meds Susan Foreman gave them being lethal to them, the Daleks attempted to vent radiation from their nuclear reactors into the atmosphere which would have left them as the only living species on Skaro. The First Doctor and his companions led a Thal assault and deactivated their power, believing that he had wiped out the Daleks altogether in the process (the necessity of which crime he lamented, though he saw no other way). (TV: The Daleks) The Doctor later correctly theorised that they were able to return because the Daleks had other colonies on Skaro. (PROSE: Doctor Who and the Dalek Invasion of Earth)

At a point where they had regained the ability to move freely outside their City, but still had not set out into space, the Daleks received a mysterious transmission which they feared might be a declaration of war. Shortly thereafter, Susan, having borrowed the Doctor's TARDIS happened to instead land in the petrified jungle on Skaro. Thinking she might be responsible for the message, or, at any rate, be able to decode it for them, the Daleks took Susan prisoner and brought her back to the City. As she stalled for time and food by decoding the message very slowly, one of the Daleks grew uncharacteristically fond of her, and even the others came to have a measure of respect for her.

Eventually, Susan realised the meaning of this message which had the Daleks so terrified: "peace and goodwill for all". She burst out laughing, startling and even terrifying many of the Daleks, who had never heard laughter in their lives. In the confusion, Susan took her chance to run off back to the TARDIS, and, despite the pleas of the lone Dalek she had befriended, she fled Skaro. The Daleks remained on a war footing for a while before finding the translation Susan had left behind and realising their error. (COMIC: The Message of Mystery)