Black Dalek Leader

After the failure of the 22nd century Dalek invasion of Earth, the Daleks identified the Doctor and a Black Dalek, under orders from the Dalek Prime, (PROSE: The Chase) ordered an assassination squad to pursue his TARDIS in a Dalek time machine. The squad failed. (TV: The Chase)

The same Black Dalek that originally organised the assassination mission, acting as a Supreme Dalek, oversaw the Dalek operations on planet Kembel in the year 4000. It was wiped out when the Doctor hijacked the Time Destructor. (TV: Mission to the Unknown/The Dalek's Master Plan) This was a massive blow for the Dalek Empire as the Dalek Prime considered both the fleet and the Black Dalek irreplaceable. (PROSE: The Mutation of Time)