Margaret Tyzack - Telegraph.co.uk

She went into repertory in Chesterfield, Derbyshire, making her first stage appearance as a bystander in Shaw's Pygmalion in 1951. For the next two years she performed as a "character juvenile" in a play a week for 48 weeks a year. She regarded this apprenticeship as the foundation of her later career, though she could remember being so exhausted that in Wuthering Heights she found herself momentarily too tired to speak.

It was in Chesterfield that she developed her soon famous audibility: "If you were warned for inaudibility on Wednesday and still couldn't be heard on Thursday, you'd be sacked on Friday. You had to learn quickly," she recalled. For the rest of her career she preferred working in Victorian or Edwardian theatres – "that wonderful old horseshoe shape"– not only because "you always know you can be heard" but also because "the architects who built those theatres knew something that a lot of modern architects don't know."

Margaret Tyzack made her London debut in 1959 in a Sunday night tryout of Alun Owen's Progress to the Park at the Royal Court, and went on to play Miss Frost, the genteel spinster seduced by Sebastian Dangerfield, in JP Donlevy's The Ginger Man.

A long association with the Royal Shakespeare Company began with a role as Vassilissa in Gorki's Lower Depths (Arts, 1963) and she was rarely out of work in the years that followed.

After her television roles brought Margaret Tyzack to the attention of audiences across the Atlantic in the mid-1970s, she spent three years on stage at Stratford, Ontario, where she played Mrs Alving in Ibsen's Ghosts, Queen Margaret in Richard III and the Countess of Roussillon.

On her return to England in 1979 she was the landlady in Athol Fugard's kitchen sink drama People Are Living There, "swooping from the highest notes of aggressive hysteria to the lowest register of humiliation and despair" according to one critic. In 1985 she won high praise for her performance on Broadway as Rose, Viv's mother, in Tom and Viv, Michael Hastings's play about the troubled marriage between TS Eliot and Vivienne Haigh-Wood.

Margaret Tyzack's partnership with Maggie Smith was revived in 1993 when she played Miss Prism to Smith's Lady Bracknell in The Importance of Being Earnest at the Aldwych. The two were again reunited three years later when they appeared together in a production of Alan Bennett's Soldiering On.

Throughout her stage career Margaret Tyzack made regular appearances on the big screen. She was Elena in Stanley Kubrick's 2001: A Space Odyssey (1968) and a conspirator in his A Clockwork Orange (1971). In 1987 she was Madame Lambert in Stephen Frears's film of Joe Orton's Prick Up Your Ears and in 1997 was Lady Bruton, reactionary pillar of empire, in Marleen Gorris's film of Virginia Woolf's Mrs Dalloway. Other film credits include The Whisperers (1967), Stephen Fry's Bright Young Things (2003), Richard Claus's The Thief Lord (2005) and Woody Allen's Match Point.

Her television credits included Quatermass, Young Indiana Jones, Miss Marple, Our Mutual Friend and Dalziel & Pascoe.

Her last stage appearance was as Oenone, Helen Mirren's elderly nurse in Nicholas Hytner's production of Phèdre at the National in 2009. Earlier this year she made a brief appearance as Lydia Simmonds in EastEnders until illness forced her to withdraw.

Margaret Tyzack was a modest, unassuming woman who liked to boast that she could go shopping without being recognised and remained unfazed by the glitz of acting award ceremonies. When she picked up the Critics' Circle best actress award for her role as Mrs St Maugham, she gave her fellow actors a lesson in how to accept by applying what she called "the three Gs: be grateful, gracious – and get off".

Margaret Tyzack was appointed OBE in 1970 and CBE in 2010. She married, in 1958, the mathematician Alan Stephenson, with whom she had a son.