Gold Dalek

Gold Daleks, also referred to as Golden Daleks, (PROSE: Doctor Who and the Day of the Daleks) were a high-ranking class of Daleks within the Dalek Empire prior to the Last Great Time War. They were denoted by their gold casing.

History
Gold Daleks were the highest-ranked Daleks within the Dalek hierarchy with the exception of the Dalek Emperor or the Dalek Prime, above Grey Daleks, Blue Daleks, Red Daleks, Black Daleks, (PROSE: War of the Daleks) and Silver Daleks. (TV: Death to the Daleks) They appeared some time after the end of the Dalek Civil War at the culmination of the Great War. (TV: The Evil of the Daleks, PROSE: The Evil of the Daleks) They could act in the place of Black Daleks as a Supreme Dalek. (TV: Day of the Daleks)

A Gold Dalek was in charge of the planet Earth in an alternate timeline where the Second World Peace Conference had failed and the Daleks invaded in the 22nd century in the aftermath of the devastating wars which followed. When the Third Doctor threatened to negate the timeline, the Gold Dalek led the Daleks and their Ogron servants back to the 20th century to ensure the Conference failed. They advanced into the Auderly House which was then destroyed by Shura using a Dalekanium bomb, taking them with it. (TV: Day of the Daleks) One account claims a Black Dalek was present as a second-in-command and was responsible for much of the Gold Dalek's tasks while the Gold Dalek acted as an overseer. (PROSE: Day of the Daleks)

On the eve of the Second Dalek War of the 26th century, a Gold Dalek led a platoon of Daleks to meet the Master on the Ogron homeworld. There, it ordered the Master's captives — including the Third Doctor, Jo Grant, General John Williams and the Draconian Prince — exterminated. However, the Master convinced the Daleks to leave the prisoners under his supervision until the Daleks' planned war began, to which the Daleks agreed and left the planet. Later, the Doctor managed to escape the prison cell by using the Master's hypnosound device, which caused the Ogron on guard to perceive the Doctor as the Gold Dalek and he opened the cell out of fear. (TV: Frontier in Space)

Following the end of the Imperial-Renegade Dalek Civil War, Dalek forces were divided as some supported Davros while others supported the Dalek Prime. The Gold Daleks were the only rank that remained fully loyal to the Dalek Prime which gave him an advantage when a brief but destructive civil war broke out on Skaro. They were aware that their power would be diminished if Davros took over. (PROSE: War of the Daleks)

Other Gold Daleks
The early Dalek Emperor, later the Dalek Prime, had a distinct gold casing made of Flidor gold. (COMIC: Genesis of Evil, PROSE: The Chase, War of the Daleks)

Following the Third Doctor's escape from the captivity of the Master and the Daleks, (TV: Frontier in Space) he had the Time Lords send him to Spiridon where the Daleks were in the process of waking up an army from under the ice. There, a black Supreme Dalek with a golden dome, solar panels and globes arrived on the planet to take charge of the mission and was said by the Thals to be a member of the Supreme Council (TV: Planet of the Daleks) Another Dalek Supreme with the same casing was part of a mission on Kar-Charrat to obtain information from the planet's Library. It was the immediate subordinate to the Emperor. (AUDIO: The Genocide Machine)

By the end of the Second Dalek War, many Daleks had been given a sturdier bronze and gold casing and Dalek X, the Dalek Inquisitor General, had a black casing with golden globes and solar panels. (PROSE: Prisoner of the Daleks)

Davros's Imperial Daleks had white casings decorated with gold, including their globes, indicator lights, gunsticks, manipulator arms, neck casings and eyestalks. (TV: Revelation of the Daleks, Remembrance of the Daleks)

A Dalek Supreme was on Red Rocket Rising to destroy Martez's Daleks to ensure the blood of the Daleks remained pure. Its casing's colours were gold and crimson. (AUDIO: Blood of the Daleks)

A Supreme Dalek commanded the invasion of Gallifrey. It had bronze and gold casing with black dome and globes. (AUDIO: Extermination, Ascension)

During the Last Great Time War, the bronze and gold casing from the Second Dalek War became standard for Dalek drones (TV: Dalek, The Last Day, The Day of the Doctor, PROSE: Engines of War) and a similar look was used for the Emperor. (TV: The Parting of the Ways) These casings were eventually used again for the foot soldiers of the New Dalek Paradigm. (TV: Asylum of the Daleks, The Time of the Doctor, Into the Dalek, COMIC: The Dalek Project, PROSE: The Dalek Generation) The New Paradigm variant of Red Daleks were similarly laced with gold. (GAME: The Doctor and the Dalek)

The red Supreme Dalek of the New Dalek Empire had golden globes and extra gold casing. (TV: The Stolen Earth/Journey's End)

Behind the scenes

 * According to the non-narrative material in The Dalek Handbook, the civil war between the Dalek Emperor's guards and the Humanised Daleks (TV: The Evil of the Daleks) ended in a victory for the Emperor's forces. Afterwards, the Emperor revamped the Dalek command structure, which involved completely replacing Black Supreme Daleks and Dalek saucer commanders with Gold Dalek Commanders for a time. While the TV series does not necessarily contradict this, other stories such as the Day of the Daleks novelisation and War of the Daleks depict Gold Daleks and Black Daleks coexisting, and The Threat from Beneath, set during the Third or Fourth Doctor's era, has the Daleks led by a Black Dalek Commander without so much as a mention of a Gold Dalek.
 * The Eternal Dalek of the New Dalek Paradigm introduced in TV: Victory of the Daleks has a similar colour-scheme to the Gold Daleks since both have black globes. However, the Eternal Dalek has a solid yellow casing instead of gold.
 * Nicholas Briggs voices the Gold Dalek (and the other Daleks) in the Day of the Daleks Special Edition DVD.
 * A Gold Dalek, alongside a Black Dalek and a Red Dalek, leads the 22nd century Dalek invasion in Daleks' Invasion Earth 2150 A.D., a non-canon retelling of The Dalek Invasion of Earth starring Peter Cushing. This was the first Gold Dalek to be seen on colour film but they would not be seen on the proper series until Day of the Daleks.
 * The Gold Dalek is referred to as "the Golden Dalek" in Terrance Dicks's novelisation of Day of the Daleks.
 * The novelisation of Frontier in Space does not describe whether the lead Dalek is gold or not, simply referring to it as "a Dalek".
 * John Scott Martin operated the Gold Dalek in both Day of the Daleks and Frontier in Space episode six, being credited as "Chief Dalek" in Radio Times on both occasions.
 * Gold Daleks feature on the covers for the VHS, laserdisc and DVD releases of Day of the Daleks, the 1994 Polish cover of the novelisation, and on the cover of the box for the Eighth Doctor Big Finish audio anthology Dark Eyes 4.
 * In Chapter 8 of Engines of War, at least one member of the Eternity Circle is described as having a blue and gold casing. However, the rest of the novel describes all five members as having a blue and silver casing. This single reference to one of them having a partly-gold casing was likely an error.