Acting must be the best rejuvenation pill on the market. If you want proof, you have only to look at the extraordinary, long-lasting career of Claire Bloom, who, somewhat incredibly, turns 90 on 15 February. She made her stage debut at the age of 15, became globally famous at 20 playing opposite Charlie Chaplin in Limelight and, in recent years, has been seen in numerous films, including The King’s Speech, and on television in Stephen Poliakoff’s Summer of Rockets. To be famous young and still working 70 years later shows not just stamina and dedication but genuine, enduring talent.

I have only met Claire Bloom once and was awestruck by her beauty. But beauty will only take one so far as an actor and from the outset Bloom clearly had enormous power in reserve: when she played Ophelia at Stratford in 1948 – opposite the alternating, radically different Hamlets of Paul Scofield and Robert Helpmann – Kenneth Tynan observed how the words “If-thou-hadst-not-come-to-my-bed” were “isolated and driven home like a coffin nail”.

Bloom’s big break came when, while she was appearing on the London stage in Jean Anouilh’s Ring Round the Moon, she was invited by Chaplin to go to New York to do a screen test for Limelight: the role was that of a young dancer who is rescued from suicide by a famous clown and who, under his tutelage, slowly regains her self-confidence. After some delay, Bloom finally got the role and has recorded her surprise at Chaplin’s working methods. “Chaplin,” she said, “was the most exacting director not because he expected you to produce wonders of your own but because he expected you to follow unquestioningly his every instruction.” For an intelligent young actor with what she termed “high creative aspirations”, this must have been daunting, but her performance is much the best thing in a sentimentally melancholic movie.

Bloom shrewdly went on to play Shakespearean lead roles at the Old Vic in the 1950s. Tynan was in raptures about her Juliet, claiming that, while the average Juliet sings the part sweetly and chants it demurely, “Miss Bloom is impatient and mettlesome, proud and defiant, and no mere blindfolded, milk-fed mite”; he went on to describe her performance as “pure gold”. While forging a career in the classics, Bloom continued to make movies, appearing in Richard III, Alexander the Great and The Brothers Karamazov. But, although she never lacked work, there was a sense that her true abilities had never been fully realised.

Far from coasting through her middle years, Bloom took on new challenges in three stage performances I was lucky enough to see. In 1973, she was Nora in Ibsen’s A Doll’s House and brought out beautifully the Viking madness of the big dance scene and the brittle hysteria induced by a life of domestic role-playing. Then in 1974 she played Blanche in A Streetcar Named Desire and conveyed to perfection a woman whose aristocratic pose conceals both a genuinely poetic soul and an emotional desperation. In 1977, she played another damaged idealist, Rebecca West, in Ibsen’s Rosmersholm, and, although I wanted a bit more crusading fervour, I would lay the blame on the production rather than the performer.

One of the great things about Bloom is that she has never stopped acting. In the 1980s she was a superbly glacial Lady Marchmain in Charles Sturridge’s TV version of Brideshead Revisited, played Joy Davidman in the original small-screen version of Shadowlands and even turned up in Woody Allen’s Crimes and Misdemeanors in which, as David Thomson wrote, “she had so little to do it was disconcerting to have her doing it”. But there was never any doubt as to her strong intelligence and independence of spirit. In 1996, she wrote a second memoir – the first was Limelight and After – significantly entitled Leaving a Doll’s House. In it she provided a candid, excoriating portrait of life with her third husband, Philip Roth, that prompted him to retaliate in one of his later fictions.

You could argue that the memoir reveals an essential truth about Bloom. She has had a hugely successful career, has fulfilled the “high creative aspirations” of her youth and at 90 is widely loved and respected. But beneath the poise and elegance there is a woman of fierce passions and finely tempered steel.