Dalek Emperor
At least four different incarnations of the Emperor Dalek are known to have existed. Davros assumed the identity of the Emperor at one point. We do not know if the same Dalek assumed the title of Emperor on occasions when Davros did not fill the role.
History
Dalek Prime
One of the first Daleks, who exterminated Davros and proclaimed the Dalek's future victory over the universe (DW: Genesis of the Daleks), assumed the role of Dalek Prime (later Emperor) would continue to act as the Emperor throughout Dalek history. (PDA: War of the Daleks)
- During the time that Davros himself assumed the position of Emperor, this may mean that two Emperor Daleks existed at the same time, opposing each other:
The Dalek Chronicles Emperor
After the nuclear war that devastated Skaro, the mutants had survived in the casings. The only humanoid Dalek survivors of the war, Yavelling and the warlord Zolfian encountered a Dalek that persuaded them to build more Dalek casings for their mutated descendants. Before the last two humanoid Daleks died, a special casing was built for the Emperor to reflect its new rank. It was slightly shorter than the other Daleks, with a disproportionately large spheroid head section and in gold rather than grey. (DC: Genesis of Evil)
The Emperor within the Dalek City
The next known incarnation of the Emperor remained in was an enormous immobile conical shell plugged into a corner of the control room in the Dalek City on Skaro and connected to the wall by tubes. It spoke in a echoing voice. (DW: The Evil of the Daleks)
- Though this has no on-screen support, some conjecture that this Emperor had originally been the Dalek who had apparently exterminated Davros and vowed that the Daleks would conquer the universe. (DW: Genesis of the Daleks)
This Emperor was apparently destroyed by a civil war between Humanized Daleks and un-altered Daleks. However, a light was seen still blinking on its casing at the end indicating some kind of activity. (DW: The Evil of the Daleks)
Davros as Emperor
Davros was made into the Emperor of the Imperial Dalek faction of the Daleks. He was greatly deteriorated physically and reduced to a head and partial torso in a customised Dalek casing. He was last seen heading for an escape pod just before his ship was destroyed in the wake of the supernova that consumed Skaro. (DW: Remembrance of the Daleks)
The Emperor during the Time War
Another Dalek Emperor ruled during the Last Great Time War and was believed to have been destroyed at the end of the war, however its ship had barely survived the war, falling through time and afterwards it went into seclusion and went on to rebuild a new race of Daleks. This Emperor was a Dalek mutant floating in a transparent tank of liquid, topped by a giant-sized Dalek dome, complete with eyestalk, and flanked by panels of armour dotted by Dalek "bumps". Because this Emperor had recreated the Dalek race, it saw itself as a god, and had transformed its Daleks from fascists to religious fanatics centred around them worshipping it. This Emperor was apparently destroyed with the rest of the Daleks by Rose Tyler after she had absorbed the energies of the time vortex and became the Bad Wolf entity. (DW: The Parting of the Ways)
The Master faced the Dalek emperor at least once after he was revived, when the Emperor took control of the Cruciform. (DW: The Sound of Drums)
Behind the Scenes
Other Dalek Emperors
A Dalek Emperor also appears in the Dalek Empire series of audio plays by Big Finish Productions. In the Eighth Doctor audio adventure Terror Firma, taking place after Remembrance of the Daleks, Davros's increasingly unstable mind is obliterated by a totally Dalek personality, that of the Emperor. This new Emperor then takes command of Davros's Daleks and departs. Whether this is the Emperor seen in the rest of the Big Finish Dalek audios is unclear.
A Dalek Emperor, described similarly to the Emperor in The Evil of the Daleks, appears in the Telos novella The Dalek Factor by Simon Clark. It is referred to as "an" Emperor, implying there was more than one at that time.