While his creations suffered the ultimate defeat at the end of the Time War, the final fleet scattered to dust by the Bad Wolf, Davros survived. Rescued from death in an early battle at the Gates of Elysium by Dalek Caan, Davros was determined to re-build the Dalek race from his own flesh. A slow construction and breeding programme was initiated by the new Dalek race. Dalek Caan, damaged and driven insane by his breaching of the time-lock surrounding the Time War became a seer for the new Dalek race. Seen as an abomination by the new breed, Caan was tolerated, chained and kept alive in the Dalek command ship to advise Davros and the Dalek Supreme.
Slowly, in secret, Davros rebuilt the Dalek race in a secret location. Each Dalek was created from a single cell of pure Kaled stock, taken from the only source in existence – Davros himself. By the time the Dalek forces have reached sufficient numbers, the Kaled scientist had virtually no skin or muscle tissue left on his chest. Davros plan to rebuild reality himself in his own image required the precise alignment of twenty-seven worlds. Hidden within the Medusa Cascade which was moved one second into the future of the rest of the universe, Davros developed the technology to steal whole planets from their usual positions in space and place them in conjunction with each other to further his ends. In order to avoid detection by others, particularly the Ka Faraq Gatri and his collection of followers, the Daleks used vast amounts of power to pluck three worlds out of time as well as space.
At the very moment of the Dalek's triumph, their plan was foiled by The Children of Time and the entire Dalek fleet was eradicated by The Doctor and his associates. Dalek Caan had determined during his fall through time that the Daleks needed to be exterminated and carefully manipulated Davros and his new creations to bring them to this single point in space-time where he could ensure their destruction once and for all.