The Supreme Dalek, also known as the Supreme One, was in command of the New Dalek Empire, which was the second fully-fledged Dalek empire created by Davros. The Supreme reigned aboard the Crucible inside the Medusa Cascade. In 2009, he orchestrated the 21st century Dalek invasion of Earth, and oversaw the empire's plot to use the reality bomb and the stolen planets to destroy all non-Dalek life in the universe.
The Supreme Dalek was a variant of the Dalek Supreme model, with a red casing, golden sense globes, and extra slat plating connecting the grating section to the weapons platform. He also had a deeper, louder voice than the other Daleks that resembled that of the Dalek Emperor that orchestrated the Battle of the Game Station, albeit still not as deep or loud as his. He ranked above Davros, having taken control of the New Dalek Empire. As well as extra armour, the Supreme One had a third luminosity discharger, which — as with his other lights — was mounted on a small plate atop his dome.
The Supreme Dalek had a clear disliking towards the insane Dalek Caan, calling him "the Abomination". Nevertheless, he relied on Caan's prophecies to guide his actions. (TV: The Stolen Earth/ Journey's End)
The New Dalek Empire was the second generation of Daleks created by Davros. Even though Davros had been trapped in the time-locked situation of the Last Great Time War, the last surviving member of the Cult of Skaro, Dalek Caan, came from the future and somehow pulled Davros out from it. Sacrificing his own body's cells, Davros eventually created the new generation of Daleks, including the Supreme Dalek, who took control of the Empire, but allowed Davros and Caan to remain and have roles.
The first of the Children of Davros, the Supreme One commanded the 21st century Dalek invasion of Earth and reported the victory to Davros, though the latter was only interested if the Doctor had arrived. The Supreme Dalek stated that there was no sign of Time Lord activity, and that they were beyond the Doctor's reach; this statement intrigued Davros, as it sounded as if the Supreme was gloating over his victory - an impossibility in the Kaled scientist's eyes, as he had crafted the Daleks to be "above" such emotions. (TV: The Stolen Earth)
Once his forces detected the Doctor's TARDIS, the Supreme Dalek ordered it to be encased in a time prison, which allowed it to be captured and depowered. The craft was transported to the Crucible, where the Supreme One demanded that the Doctor and his companions emerge from their craft. Before Donna Noble could exit, she was distracted by the recurring sound of a heartbeat, and the TARDIS door shut her inside. The Doctor demanded that the Supreme Dalek release her; however, the Supreme Dalek stated it was not his doing, and that it was likely "Time Lord treachery". (This turned out to be the independent actions of Dalek Caan.)
The Supreme Dalek commanded his forces to dump the TARDIS into the Z-Neutrino core of the Crucible in order to destroy it. As it began to disintegrate, the Supreme Dalek asked the Doctor if he felt anger and pain, and stated that emotions make one weaker. Captain Jack Harkness then attacked the Supreme Dalek out of anger with a pistol, which did not harm the Dalek leader. The Supreme Dalek retaliated by killing Jack, unaware that he was immortal and would soon return to life, and then ordered the Doctor and Rose Tyler to be taken to the Vault.
The Doctor discovered when meeting Davros that the creator of the Daleks was not the master of the New Dalek Empire, but it was in fact the Supreme Dalek who was in charge. After being created, the Daleks turned on their creator (yet again), who made an arrangement with them; he would ensure their domination of the universe if they allowed him to live. This was to be done through the use of the reality bomb which would be powered by the 27 planetary engine configuration of the captured worlds in the Medusa Cascade in conjunction with the Crucible's energy source. This would bring about the destruction of all existence except for the Daleks, leaving them to be the masters of the universe. To ensure Davros's cooperation, the Supreme Dalek locked Davros — along with Dalek Caan — in the Vault of the Crucible.
When Doctor Donna foiled the Daleks' plot by disabling them and returning almost all of the stolen planets to their original locations, the Supreme Dalek personally descended to the Vault to investigate. There, he confronted Davros and accused him of betrayal. When Davros revealed that it was in fact Dalek Caan who betrayed them, the Supreme Dalek did not care: all would be purged from the Vault. He destroyed the magnetron control station before Earth could be returned to its place, but Jack Harkness quickly opened fire with his defabricator, blasting the Supreme Dalek to pieces. (TV: Journey's End)
Like previous and subsequent Supremes, the Supreme Dalek in charge of the New Dalek Empire was demanding, expecting his subordinates to obey him without question. Like most Daleks in a position of authority, he had more individual personality than other Daleks. He was confident to the point of arrogance and Davros suggested he could detect a hint of pride in the Supreme Dalek's voice. The Supreme Dalek was also highly racist and prejudiced, even by the standards of a Dalek, keeping all non-Daleks in a separate area called the Vault, as apparently considering them sources of contamination. He was also very suspicious of others, stating that the TARDIS acting on its own must be "Time Lord treachery", accusing Davros of treachery after Dalek Caan betrayed them and prior to that, referring to Caan as "the abomination" and "insane". Unusually for a Dalek, he seemed to have something resembling a sense of humour, saying that the Doctor and his companions would be "the playthings of Davros" before having them sent to the Vault. He even cruelly ridiculed the Doctor when it appeared that Donna had died, asking what emotions he felt in a mocking tone which prompted Captain Jack to shoot him. Despite his confidence, the Supreme Dalek seemed to have a certain level of respect and even fear for Davros, despite keeping him prisoner, as he listened to his advice, kept him informed of all situations, obeyed direct orders from him, and remained completely silent when Davros would reproach him. (TV: The Stolen Earth/ Journey's End)
Behind the scenes
The Supreme Dalek was depicted using a specially created prop. The dome from this Supreme Dalek prop appeared in the Black Archive in The Day of the Doctor. The full prop was later reused to depict the Supreme Dalek in The Magician's Apprentice/The Witch's Familiar.
- In a section on the design of the Supreme Dalek, Doctor Who: The Ultimate Monster Guide suggested that the enlarged gold struts allowed it to plug into flagship systems.
- The original cancelled design for the Supreme Dalek was similar to the Glass Dalek. It was to be translucent and transparent, showing internal functions and machines as well as the mutant within.