Dame Peggy Ashcroft, an actress who was in the forefront of British theater for more than half a century, died yesterday in London. She was 83 years old. She suffered a stroke on May 23 and was unconscious in the Royal Free Hospital since then, a spokeswoman for the hospital said. Dame Peggy was in the Old Vic company in the early 1930's, frequently appearing with John Gielgud in the 1930's and 40's. She often performed in the West End of London in the 1950's and with the Royal Court, the Shakespeare Memorial Theater, the Royal Shakespeare Company and the National Theater. She was made a Dame of the British Empire in 1956 and in 1962 she became the first British actress to have a theater -- the Ashcroft, in her hometown, Croydon -- named after her in her lifetime. When she was in her mid-70's Dame Peggy won her greatest international acclaim from roles involving two visits to India. She played a saintly, enigmatic Englishwoman in David Lean's film of E. M. Forster's novel "A Passage to India" and then was cast as a doubting former missionary in a television mini-series, "The Jewel in the Crown," based on Paul Scott's "Raj Quartet." She won a 1984 Academy Award as best supporting actress for the film; the New York Film Critics Circle voted her best actress. The two performances brought her Britain's top film and television awards. She had previously won a string of awards as the finest actress on the British stage, and in April she won a special Laurence Olivier Award, London's major theatrical prize, for lifetime achievement in the theater. Dame Peggy was praised as a natural actress who projected an inner serenity and moral gravity. She illumined all of Shakespeare's young leading women and was hailed as the finest Juliet of her generation, artfully attuning her performances to Gielgud and Olivier versions of Romeo and Mercutio as the actors alternated in the roles throughout a season. Detractors called some of her early performances too genteel and cool, too English bourgeois, but over the decades she displayed increasing versatility in plays by Shaw, Sheridan, Chekhov, Wilde and Ibsen. With uncommon ease she worked closely with new generations of theater people and in later years played Shakespearean matrons and roles created by Edward Albee, Marguerite Duras, Harold Pinter and Beckett. Her talents included portraying the rejected, the lonely and the oppressed with unsentimental sympathy. As Winnie in Beckett's "Happy Days," she was required to spend the first half of the performance buried up to her waist, the second half to her neck. It's "the greatest part ever written," she said, "nearer to Everywoman than any other I can think of, and like climbing Everest to perform." In approaching hundreds of roles, including 10 leads in a season at the Old Vic, she tirelessly sought psychological truths. "Acting," she said in 1985, "is a mysterious business, so complicated, so tender a subject, there are no rules, and I think one works instinctively." Defining her art in "Peggy Ashcroft," a 1988 biography, the critic Michael Billington cited her ear for language, her emotional identification with characters and avoidance of vulgarity and affectation. Sir John Gielgud spoke of the actress's "shimmering radiance and a kind of forthright, trusting quality." The director Peter Hall said she maintained in old age an "extraordinary immediacy and passionate naivete." Harold Pinter said, "This flame of life she possesses informs all she does." Dame Peggy appeared in only a few movies. Her most memorable early one was a vignette in Alfred Hitchcock's 1935 thriller, "The 39 Steps," as a farmer's wife who bravely aids the hero (Robert Donat). In making films she missed the theater's long, searching rehearsals. The problem with films, she said, "is that you have to imagine everything in sufficient detail before you begin." "With the theater," she added, "there is time to try things out. With filming, it is hit or miss." She said appearing in films was "instant acting" because a film actor might have to begin at the end of a scene or a movie and not be able to build a role. "Also, you're in the hands of a director and an editor who can cut and shape, and you have no idea how," she said. "And, of course, there's no sharing with an audience, no rapport." Dame Peggy said she had no desire to retire. "Just a rest after the rather full years I had in India," she said in 1985. "Then I'll wait and see what television or film or the theater bring." She cherished privacy and granted few interviews, once explaining gently, "I'm not interested in myself, very." But she was outspoken in protesting injustices and inhumaneness, at home or abroad. She criticized apartheid in South Africa and protested the sentencing of a Soviet dissident, Vladimir Bukovsky, and political arrests in Czechoslovakia. Edith Margaret Emily Ashcroft was born on Dec. 22, 1907, in Croydon, a London suburb, to William Worsley Ashcroft, an estate appraiser, and the former Violetta Maud Bernheim. Her father was killed in World War I when she was 10 and her mother died when she was 18, leaving her elder brother, Edward, as her only close relative. She studied at the Woodford School in Croydon and after discovering "it was very exciting to become someone else," she said, she enrolled at the Central School of Speech and Drama in London. Her varied roles included Desdemona to Paul Robeson's Othello in 1930, stardom as Juliet and Shakespeare's other golden girls, as she called them, and title roles in Shaw's "Caesar and Cleopatra," John Drinkwater's "Mary Stuart" and Arthur Schnitzler's "Fraulein Elsa." A 1989 biography of Paul Robeson by Martin Bauml Duberman revealed that Dame Peggy and the actor had had an affair during the run of "Othello," and quoted her as saying, "How could one not fall in love in such a situation with such a man?" Later roles included an alcoholic mother in "Edward, My Son," in both London and New York; an unloved spinster in "The Heiress," leading parts in Brecht's "Good Woman of Setzuan," Ibsen's "Hedda Gabler" and "Rosmersholm" and the 10-hour tour de force as Margaret of Anjou in the Royal Shakespeare Company's "Wars of the Roses." Dame Peggy was married and divorced three times. She is survived by two children, Nicholas, a director, and Eliza, by her third husband, Jeremy Hutchinson, a lawyer. Her previous husbands were Rupert Hart-Davis, a publisher, and Theodore Komisarjevsky, a director.