Dame Agnes Sybil Thorndike, Lady Casson (24 October 18829 June 1976), was an English actress whose stage career lasted from 1904 to 1969.

Trained in her youth as a concert pianist, Thorndike turned to the stage when a medical problem with her hands ruled out a musical career. She began her professional acting career with the company of the actor-manager Ben Greet, with whom she toured the US from 1904 to 1908. In Britain she played in old and new plays on tour and in the West End, often appearing with her husband, the actor and director Lewis Casson. She joined the Old Vic company during the First World War, and in the early 1920s Bernard Shaw, impressed by seeing her in a tragedy, wrote Saint Joan with her in mind. She starred in it with great success. She became known as Britain's leading tragedienne, but also appeared frequently in comedy.

During the Second World War, Thorndike and her husband toured in Shakespeare productions, taking professional theatre to remote rural locations for the first time. Towards the end of the war she joined Ralph Richardson and Laurence Olivier for two seasons staged by the Old Vic company in the West End. After the war she and Casson made many overseas tours, playing in Europe, Asia, Africa and Australia. They also appeared on Broadway.

Thorndike was mainly known as a stage actress, but made several films from the 1920s to the 1960s, among them The Prince and the Showgirl (1957) and Uncle Vanya (1963), both with Olivier. She also broadcast from time to time on radio and television. Her last stage appearances were in 1969 at the theatre named in her honour, the Thorndike Theatre, Leatherhead.

Early years Thorndike was born on 24 October 1882 in Gainsborough, Lincolnshire, the eldest of the four children of the Rev Arthur John Webster Thorndike (1853–1917) and his wife Agnes Macdonald, née Bowers (1857–1933), the daughter of a shipping merchant.Morley, Sheridan. "Thorndike (married name Casson), Dame (Agnes) Sybil", Oxford Dictionary of National Biography, Oxford University Press, 2011 From both parents Thorndike learned values of tolerance and concern for others that remained with her throughout her life.Croall, pp. 14−15 When she was two years old her father was appointed a minor canon of Rochester Cathedral.Croall, pp. 11–12 She was educated at Rochester Grammar School for Girls, and first trained as a classical pianist, making weekly visits to London for lessons at the Guildhall School of Music.

In May 1899 Thorndike gave her first solo piano recital, but shortly afterwards she developed recurrent pianist's cramp, and although she performed in leading concert venues in London – the Bechstein, Steinway and St James's halls – by 1902 it was clear that a musical career would be impossible.Croall, pp. 28 and 33–34 She studied for the stage at the drama school run by Ben Greet, who engaged her for an American tour beginning in August 1904, in advance of which she made her professional début at Cambridge in June, as Palmis in W. S. Gilbert's The Palace of Truth.Morley (1986), p. 384 She remained in Greet's company for three years playing in Shakespearean repertory throughout the US.Herbert, p. 1476

On her return to England, Thorndike was spotted by Bernard Shaw in a one-off Sunday night performance at the Scala Theatre in London; he invited her to join the company for a revival of his Candida to be given in Belfast by Annie Horniman's players. The company was based at the Gaiety Theatre, Manchester, where she first appeared in September 1908 as Bessie Carter in Basil Dean's Marriages are Made in Heaven. She played parts in nine other plays by authors ranging from Euripides to John Galsworthy.Croall, pp. 524−525 In the company she met, and formed a lifelong partnership with, the actor Lewis Casson. They married in December 1908 at her father's church. They had two daughters and two sons, all of whom went on the stage for some or all of their careers.

Thorndike appeared at the Coronet Theatre, London, in June 1909 with the Horniman company, and at the Duke of York's Theatre in March 1910 with Charles Frohman's repertory company, appearing there as Winifred in The Sentimentalists, Emma Huxtable in The Madras House, Romp in Prunella and Maggie Massey in Chains. She then went to New York, where she appeared at the Empire Theatre in September 1910, as Emily Chapman in Smith opposite John Drew.

Between her return to Britain and the outbreak of the First World War in 1914, Thorndike appeared in the West End at the Aldwych Theatre in June 1912 as Beatrice Farrar in Hindle Wakes, and at the Playhouse Theatre in July 1912 in the same role. She returned to Manchester for a second season at the Gaiety later in the year, playing a range of roles in nine plays. At the Court Theatre in London in May 1913 she played the title role in St John Ervine's Jane Clegg, and in October she appeared in both Manchester and London as Hester in Eden Phillpotts' The Shadow."The Shadow", The Era, 8 October 1913, p. 17

1914–1919

Between November 1914 and May 1918 Thorndike played in four seasons at the Old Vic (and one at the Shakespeare Memorial Theatre in 1916) with a mostly Shakespearean repertory.Croall, pp. 526–527 According to her biographer Jonathan Croall, she played "most of the main female characters" and – with a shortage of young actors during the war – she took six male roles including Prince Hal in Henry IV Part 1, the Fool in King Lear, Ferdinand in The Tempest and Puck in A Midsummer Night's Dream. Her non-Shakespearean roles included Lady Teazle in The School for Scandal, Peg Woffington in Masks and Faces, Kate Hardcastle in She Stoops to Conquer, the Angel Gabriel in the mystery play The Star of Bethlehem, and Nancy in a stage version of Oliver Twist adapted by her brother Russell, who was the leading man of the company. Together, the siblings wrote and co-starred in two revues for the company: The Sausage String's Romance, or a New Cut Harlequinade and Seaman's Pie, a Naval Review of Revues and Other Things.

After leaving the Old Vic company, Thorndike was engaged by C. B. Cochran and appeared at the Oxford Music Hall, London, in June 1918 as Françoise in a sketch, "The Kiddies in the Ruins", which was introduced into The Better 'Ole. In various West End theatres during 1919 she appeared as Sygne de Coûfontaine in The Hostage, Naomi Melsham in The Chinese Puzzle, Clara Bortswick in The Great Day, Anne Wickham in Napoleon and in October she played Hecuba in The Trojan Women, adding to her growing reputation as Britain's leading tragedienne."A great tragedienne: Sybil Thorndike as Hecuba", The Sketch, 25 February 1920, p. 309 Praising her as "a new leading lady" for the West End, The Times predicted, "Much as the Old Vic will regret it, it is hardly conceivable that Miss Thorndike will be allowed to cross over to the south side of the river again"."A New Leading Lady", The Times, 29 April 1919, p. 14 In the event, she continued to appear in Old Vic productions as well as in the West End for nearly thirty years.Herbert, pp. 1476−1478

1920s In early 1920 Thorndike successfully repeated her Hecuba and played the title roles in Shaw's Candida and in another Euripides play, Medea. The critic J. T. Grein wrote of the latter, "It is a great example of tragic acting, and a magnificent achievement"."A great tragic actress: Miss Sybil Thorndike as Medea", Illustrated London News, 13 March 1920, p. 395 Later in the year Thorndike joined her brother and her husband in a two-year run of Grand Guignol melodramas at the Little Theatre.Morley (1986), p. 384

The vogue for theatrical horror began to wane and Casson and Thorndike joined Bronson Albery and Lady Wyndham in the management of the New Theatre in 1922. They opened with Shelley's verse tragedy The Cenci. Shaw saw a performance, and told his wife, "I have found my Joan".Morley (1986), p. 385 He was planning a play about Joan of Arc, which he completed in 1923.Holroyd, p. 523 It was his custom to open his plays on Broadway before their West End premieres, and the first actress to play his Joan was Winifred Lenihan, but the part was written with Thorndike in mind.

Saint Joan opened at the New Theatre in March 1924.Herbert, p. 1477 Thorndike's performance received praise from the critics, but there were reservations: in The Times, A. B. Walkley said that she performed beautifully, but he found her "rusticity of speech a superfluity". The critic of The Daily Telegraph felt that no other actress could have better "hit off the Maid's simplicity without losing her strength". Desmond MacCarthy in the New Statesman, praised Thorndike for emphasising the "insistive, energetic, almost pert traits of the Maid as Mr Shaw conceives her" but thought she missed "the sweetness and simplicity of the Maid's replies and demeanour in the trial scene" though driving home Joan's "distress, her alertness, her courage".Quoted in Tyson, p. 95 In The Observer, Lennox Robinson wrote that Thorndike's performance "was beautiful, was entirely satisfying. Mr Shaw was, indeed, nobly served."Robinson, Lennox, "At the Play", The Observer, 31 March 1924, p. 11 The initial London production ran for 244 performances, and Thorndike starred in revivals over the following 17 years not only in London (1925, 1926, 1931 and 1941) but at the Théâtre des Champs-Élysées, Paris (1927) and on tours of South Africa (1928) and the Middle East, Australia and New Zealand (1932−33).Croall, pp. 529–532

In 1927−28 Thorndike was again a member of the Old Vic company, for a season at the Lyric Theatre, Hammersmith. She played Katherina in The Taming of the Shrew, Portia in The Merchant of Venice, Beatrice in Much Ado About Nothing and Chorus and the Princess of France in Henry V.

In the 1920s Thorndike entered films, appearing in four: as Mrs Brand in Moth and Rust (1921), various parts in Tense Moments from Great Plays (1922), Edith Cavell in Dawn (1928) and the Mother in To What Red Hell (1929). In 1923 she made her first radio broadcasts for the BBC; during the decade these included two of her best-known stage roles: Medea and Saint Joan.Croall, pp. 537−538

1930s Thorndike's roles of the early 1930s included the title part in Racine's Phèdre, Mrs Alving in Ibsen's Ghosts, and Emilia in a celebrated production of Othello at the Savoy Theatre with Paul Robeson and Peggy Ashcroft as Othello and Desdemona.Croall, pp. 233, 234 and 237 In 1931 she was appointed DBE, the fourth actress to be made a Dame.Gaye, p. 1579 She appeared in a wide range of plays, both classical and modern, often under Casson's direction.

From April 1932 to April 1933 Thorndike and Casson made a tour of Egypt, Palestine, Australia and New Zealand, in which she appeared in the satirical comedy Advertising April; Shaw's Captain Brassbound's Conversion; Ghosts; Clemence Dane's Granite; Macbeth; a romantic comedy, Madame Plays Nap; Milestones; The Painted Veil; Saint Joan and Sidney Howard's domestic drama The Silver Chord.Herbert, p. 1478; and Croall, p. 532