Jaime Winstone will be among the four actresses playing Dame Barbara Windsor in a BBC1 biopic of the ex-EastEnders star.
Samantha Spiro will take on the role of the actress later in life, while two child actors will appear to depict her younger years.
Dame Barbara will also make a cameo appearance in the 90-minute drama written by Tony Jordan, entitled Babs.
Jaime, who will be playing the Carry On star in her 20s and 30s, said: "It is a complete honour to play Dame Barbara Windsor.
"It is a role I have manifested for years and am so excited to step into her national treasure shoes! I have always been a huge fan of Barbara and to be able to play her throughout this stage in her life is gonna be very special. I can't wait to start filming."
Preparing to perform in the theatre one cold evening in 1993, the drama sees the actress reflect on the people and events that have shaped her life and career from 1943 onwards.
She will contemplate her lonely childhood and her evacuation during the Second World War, her complicated relationship with her father, her marriages, capturing the attention of theatre director Joan Littlewood and becoming the blonde bombshell in the Carry On films, according to the BBC.
Samantha, who previously portrayed Dame Barbara in the 1998 stage play Cleo, Camping, Emmanuelle And Dick and in the television production of Cor Blimey!, will play the actress in her 50s.
She said: "It's absolutely thrilling to be playing Barbara again. Tony Jordan has written a beautiful celebration of her life, but it's not your usual biopic, lots of surprises!
"She is so adored, so I hope we get it right and that Barbara herself loves it!"
Dame Barbara added: "I am truly thrilled to know that the BBC have secured two such talented and established actresses to portray me in their new biopic of my life.
"Sam Spiro has already proved herself playing me on stage and TV to great acclaim, as well as having her own incredible career.
"Sam will now be playing me at a later time in my life which will be a new challenge for her and one she will undoubtedly achieve.
"And then to be lucky enough to have one of today's current dynamic actresses playing the younger me fills me with such excitement, especially knowing that it is Jaime Winstone. Boy am I a lucky lady!"
The drama will go into production soon for broadcast in 2017.