When does The Black Adder return?

The Black Adder is the first series of Blackadder, written by Richard Curtis and Rowan Atkinson. Set in 1485 at the end of the British Middle Ages, the series is written as an alternative history. It contends that King Richard III won the Battle of Bosworth Field, only to be assassinated by his nephew's son Edmund and succeeded by said nephew, Richard IV, one of the Princes in the Tower. The series follows the exploits of Richard IV's unfavoured second son Edmund in his quest to increase his standing with his father.