Dalek leader

Dalek leader was a rank typically given to Dalek drones placed in charge of special missions for the Daleks. Dalek leaders regularly answered to the Supreme Dalek.

Functionally, the role was similar to Command Daleks, or Dalek Commanders, though with less emphasis on direct military missions. Similarly, there were Dalek Section Leaders, who headed scientific and research projects.

Landinalakallinian observed that Dalek Captains and their subordinate Dalek Lieutenants did not seem to be distinguishable from exterior appearance, with the Gallifreyan professor suggesting that they relied on forms of radio identification signals to identify each other instead of more obvious rank markings. (PROSE: The Dalek Problem)

History
The Dalek Prime, the earliest Dalek in existence who fired on Davros at their creation, and eventually became the Dalek Emperor, (PROSE: The Evil of the Daleks, War of the Daleks) was rallied around as the first Dalek leader during the coup. (PROSE: Doctor Who and the Genesis of the Daleks) The Emperor's leadership during the early period of the Dalek Empire was enforced by the Black Dalek Leader (COMIC: Plague of Death) and the Red Dalek Leader. (COMIC: Eve of War) The Emperor also referred to his guards as "Black Dalek Leaders". (TV: The Evil of the Daleks) By one account though, "the original Dalek leader" was the Dalek Supreme who ruled the Dalek City at the time of the Thal-Dalek battle. (AUDIO: Return to Skaro)

In the original Dalek hierarchy established by the Dalek Prime, Red Dalek were designated as section leaders. (PROSE: The History of the Daleks)

During the Daleks' conflict against the Mechanoids, the Dalek Fleet was led by a Daleader. (COMIC: The Rogue Planet)

The assassination squad sent to hunt down the First Doctor in a Dalek time machine was under the command of a Dalek leader, designated as Squad Leader, though they acted under the instructions of the Black Dalek and the Dalek Prime. The Dalek leader was the final surviving Dalek during the battle with the Mechanoids on Mechanus. In a last bid to kill the Doctor, the Dalek leader set the Mechanoid City to self-destruct, killing everything inside, but the Doctor ultimately escaped. (PROSE: The Chase)

During the Dalek invasion of the 25th century, a Dalek Leader was at the head of an advance party which landed in Kent ahead of a planned invasion of Earth. However, their efforts were sabotaged by a mole. (PROSE: The Small Defender)

According to the Dalek Combat Training Manual compiled by the Time Lords during the Last Great Time War, the Gallifreyans had done "meticulous research" into the Dalek conflict against the Space Security Service, mentioning that they had discovered how "a red Dalek leader" had served as a high-ranking officer during the campaign. Nevertheless, the text did not clarify if the officer in question was the Red Dalek Leader, or merely another Dalek that had attained the rank. This leader oversaw silver Daleks and was supported by a red-domed subordinate. (PROSE: Dalek Combat Training Manual)

The Dalek expedition to Exxilon was led by a Dalek leader who was distinguished from its silver Dalek subordinates by its amber luminosity dischargers. It was destroyed when Dan Galloway blew up the Dalek saucer. (PROSE: Death to the Daleks, TV: Death to the Daleks)

A Chief Dalek, also known as the "Dalek Leader", was the leader of the Dalek space station and the operation to build a TARDIS fleet to rule the universe with the aid of Shazar. It was distinguished from the Dalek drones by its black dome. The Chief Dalek was destroyed when all TARDIS ships the Daleks built exploded by Cirenium. (COMIC: Return of the Daleks)

Also acting under the Supreme Dalek, (PROSE: Doctor Who and the Destiny of the Daleks) one grey Dalek leader commanded the mission to retrieve Davros during the Dalek-Movellan War. Its casing was coloured in the darker grey of the original Genesis Daleks with matching shoulder slats in contrast to its subordinates, which were a lighter grey with black slats and sense globes. The Dalek leader remained with Davros as the other Daleks were sent on a suicide mission to blow up the Movellan ship, but the Fourth Doctor blinded it with his hat and blew it up with an explosive (TV: Destiny of the Daleks) The Dalek leader was among the individuals remembered by the Fourth Doctor as he regenerated. (TV: Logopolis)

Following Movellan War, Alpha leaders were subordinate to the Supreme Dalek. In 4590, an Alpha Dalek followed the Supreme Dalek in the Duplicate Incident. (PROSE: Resurrection of the Daleks) Another Alpha Dalek later led a force on the Supreme's behalf in the Necros Incident. (TV: Revelation of the Daleks)

The hierarchy of the Orcini New Daleks included Third Class Dalek Leader and First Class Dalek Leader. (PROSE: War and Peace)

A group of four high-ranking bronze Daleks were assembled by the Dalek Emperor to form the Cult of Skaro in anticipation of the Last Great Time War, consisting of the Commander of the Seventh Incursion Squad, the Commandant of Station Alpha, an Attack Squad Leader in the Thirtieth Assault Group, and Force Leader of the Outer Rim Defensive Battalion. They were respectively named Sec, the designated leader of the Cult, Thay, Caan and Jast. (PROSE: Birth of a Legend) Sec identified himself as both leader and commander of the Cult of Skaro. (TV: Evolution of the Daleks)

In the Invasion of Manhattan, Caan usurped Sec as leader with the support of Thay and Jast, designating himself as Controller of the Dalek-humans, which was originally to be Sec's position, and being connected to a military computer which allowed him to take control of the new army. When the Dalek-humans turned against the Cult of Skaro, Caan used his connection to kill them before abandoning his post. (TV: Evolution of the Daleks)

Within the Parliament of the Daleks, thousands of bronze Daleks served as Dalek governors. (PROSE: Dalek: The Astounding Untold History of the Greatest Enemies of the Universe)

The leader of the Death Squad Daleks oversaw the campaign against the Defence Drones in 2021 after being summoned to Earth by the Thirteenth Doctor. Though physically similar to its Bronze Dalek subordinates, its was distinguished by its deeper voice. (TV: Destiny of the Daleks)

Parallel universes
In the Unbound Universe, the singular Black Dalek was the leader of the second generation of Daleks, though Davros noted that the Black Dalek was not meant to be a leader in the truest sense of the word, as the Daleks were designed to be equal to all of their kin, but a rather a central point for which the Daleks to base their psychology and society around. (AUDIO: Masters of War)

Behind the scenes

 * Dalek leaders are usually identified in Target novelisations, as the parent TV serials less commonly distinguish them from the other Daleks.
 * The Dalek Handbook places the grey "Dalek Leader" position as seen in Planet of the Daleks as subordinate to the Gold Commander, itself subordinate to the Dalek Supreme.