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 on when the reality bomb destroyed the universe. (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 Doctor thwarted. (TV: Doomsday) Time traveling 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. At 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, and ended up at the Gates of Elysium during the Last Great Time War. Travelling into a time-locked era ruined his mind, but he helped to save Davros from his death. Davros, like the Dalek Emperor who also survived the Time War by time travel, rebuilt the Dalek Fleet of two thousand ships and millions of Daleks — unlike the Emperor, Davros 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 such as the Supreme Dalek.

In 2009, the Daleks transported 27 planets into the Medusa Cascade from various times and places (mostly the present, but from other eras as well). 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. (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 make the destruction of all 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 Meta-Crisis Tenth Doctor destroyed the fleet and the Crucible by maximising the Dalekanium power feeds and blasting them back. (TV: Journey's End)

Legacy
Rusty, a New Paradigm Dalek, 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)