New Dalek Empire

The New Dalek Empire was founded by Davros in the aftermath of the Last Great Time War, which had destroyed the original Dalek Empire. Davros apparently lost control of this New Empire, which fell under the reign of the Supreme One.

Overview
The New Dalek Empire was very different from the prior Dalek force that was reconstituted by the Dalek Emperor after the Time War. The prior force was full of insane hybrids. (TV: The Parting of the Ways) The New Dalek Empire, however, was dramatically larger, and quite capable of combating even Time Lord technology: they could capture and disable a TARDIS. Their forces consisted of hundreds of starships with enough power to devastate the universe. Their central base of operations was the Crucible, on which the Daleks planned to reside when the reality bomb destroyed the rest of reality. (TV: Journey's End)

First attempts
The New Dalek Empire was to be the new Empire of the Daleks that the Cult of Skaro had planned to create. The very first attempt was on planet Earth with the Genesis Ark, to unlock it and unleash the Daleks within, which the Tenth Doctor thwarted. (TV: Doomsday)

Time travelling from London in 2007 to New York City in 1930, the Cult, now the last four Daleks in existence, attempted to conquer Earth and recreate the Dalek Empire. This attempt, even with the help of the Final Experiment (which included use of Pig slaves and human-Dalek hybrids) failed due to the interference of the Tenth Doctor. By the end, Dalek Caan was the last surviving Dalek in all of creation. (TV: Daleks in Manhattan/Evolution of the Daleks)

New Empire
Caan activated an emergency temporal shift to escape the Doctor in 1930, (TV: Evolution of the Daleks) and ended up at the Gates of Elysium during the Last Great Time War. Travelling into a time-locked era damaged his mind, but he helped to save Davros from his death. Davros built a Dalek Fleet of two hundred ships with millions of Daleks. He rebuilt the Daleks out of his own Kaled cells. Caan was left as a sort of prophet, and a new Supreme Dalek was created to oversee the Dalek forces.

As a result of his actions Davros, regarded Caan with immense respect and defended him against anybody who criticised him, including the Supreme Dalek. (TV: The Stolen Earth) However, no one knew that Caan was secretly plotting against them, having now realised the truth of the Daleks following his temporal shift into the Time War. (TV: Journey's End)

In 2009, the Daleks transported 27 planets into the Medusa Cascade from various times and places. The new Daleks then took control over the planets in the Cascade. In their attack on Earth, they took many humans aboard their ships, and wiped out any resistance that they met. Everything was placed one second out of sync with the rest of the universe to hide it from those who might stop them, such as the Tenth Doctor. (TV: The Stolen Earth)

The new Empire planned to use the 27 planets in conjunction with the Crucible 's energy source to power a reality bomb created by Davros, who intend to use it to destroy everything in existence and allow the Daleks to be the sole inhabitants and masters of the universe. The Supreme Dalek made an arrangement with Davros; the creator of the Daleks would ensure their domination of the universe if they allowed him to live. The plan failed by the interference of DoctorDonna, who closed off all of the Z-Neutrino energy relay loops of the reality bomb by using an internalised synchronous back-feed reversal loop, locked the Daleks' weaponry in a self-replicating energy blindfold matrix through macrotransmission of a K-filter wavelength, and interfered with the Daleks' systems with a trip stitch circuit-breaker in the psycho-kinetic threshold manipulator. The Metacrisis Tenth Doctor destroyed the fleet and the Crucible by maximising the Dalekanium power feeds and blasting them back. (TV: Journey's End)

By unknown means, Davros escaped the destruction of the Crucible, and returned to Skaro. (TV: The Magician's Apprentice)

Legacy
One saucer of the New Dalek Empire survived its fall, (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe) with its crew masterminding the Ironside Project that led to the creation of the New Dalek Paradigm, a third Dalek Empire led by purebred Daleks. (TV: Victory of the Daleks) Rusty observed visions of the New Dalek Empire's attack on the Valiant, and the Empire's destruction, when he saw into the mind of the Twelfth Doctor. In doing so, he felt the Doctor's hatred for the Daleks, and turned against his own kind, massacring the Dalek boarding party aboard the Aristotle. (TV: Into the Dalek)

Behind the scenes

 * According to the non-narrative "The Dalek Handbook", three Daleks in Victory of the Daleks were members of the New Dalek Empire and the survivors of the Medusa Cascade. Dalek: The Astounding Untold History of the Greatest Enemies of the Universe later confirmed this.
 * The Doctor Who Experience (London/Cardiff) reveals more Daleks survivors of the Crucible 's destruction. These Daleks attacked the New Dalek Paradigm.