Chief Dalek (Return of 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)

Other references
The Dalek Survival Guide noted the Gold Dalek as a Dalek Supreme yet also claimed the Dalek was never called by that rank, leading to the theory that it was actually a sub-commander or Chief. (PROSE: Dalek Survival Guide)

Behind the scenes

 * On pages of the comic the Chief Dalek's dome and lights were similar to the Dalek Supreme in Planet of the Daleks.
 * The Chief Dalek has either a rank of the Emperor's elite guards or a rank of a Black Dalek.
 * John Scott Martin, who operated the Gold Dalek in both Day of the Daleks and Frontier in Space episode six, was credited as "Chief Dalek" in the Radio Times on both occasions.