Brenda Blethyn was among the famous names who welcomed The King's Speech to the London stage, around a year after the film starring Colin Firth triumphed at the Oscars.
Dame Kelly Holmes and Gina McKee were also among the audience for the show's official opening at the Wyndham's Theatre.
David Seidler, who originally wrote the story about King George VI as a play before creating the screenplay, was also expected to attend the performance.
The film, which won four Oscars and seven Baftas, stars Firth as Bertie, the king who overcame his stammer with the help of Australian speech therapist Lionel Logue (Geoffrey Rush).
The play stars Charles Edwards in the lead role, Australian-born Jonathan Hyde as Logue, and Emma Fielding as Queen Elizabeth.
Directed by Adrian Noble, it also features Joss Ackland as King George V and Ian McNeice as Winston Churchill.
The production had its world premiere last month in Guildford, the first time it had ever been performed on the stage.
Seidler began working on the play in the 1970s and 1980s but abandoned the project when the Queen Mother asked him not to pursue it during her lifetime.
He returned to it after her death and went on to win a Bafta and an Academy Award for the screenplay.
Dame Eileen Atkins, MPs Kenneth Clarke and Harriet Harman and broadcaster Sian Williams were also in the audience tonight.