There will be four hour-long shows based on personal accounts from, and interviews with those who were close to, the comedy legends.
In Hughie Green, Most Sincerely, "a parable about the destructive power of success and celebrity", Green will be played by Trevor Eve (Waking the Dead). It is written by Tony Basgallop, directed by Dan Percival and produced by Ben Evans.
The Curse of Steptoe, about Steptoe & Son, will see Phil Davis (Five Days) play Brambell and co-star Jason Isaacs (The State Within) as Corbett. It is written by Brian Fillis, directed by Michael Samuels and produced by Ben Bickerton.
Frankie Howerd: Rather You Than Me will look at another British comedy great but is yet to be cast. It is written by Peter Harness, directed by John Alexander and produced by Ben Evans.
And, as announced last week, Ken Stott will play Hancock in another of the four hour-long productions.
All except Hancock & Joan, from World Productions, are being made in-house.
BBC Four acting controller George Entwistle said: "The season celebrates some of the most enduring icons from the history of British television.
"The dramas show a different side to the various personalities – sometimes funny, sometimes sad - always surprising and fascinating."
The shows will be aired in the Spring.