She won her first Oscar for The Prime Of Miss Jean Brodie in 1969 and went on to garner several Golden Globes and BAFTAs throughout her long career.

Dame Maggie, who has died at the age of 89, was part of a generation of female performers that included Judi Dench and Vanessa Redgrave.

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Tributes pour in for acting great who starred in Harry Potter and Downton Abbey

Born Margaret Natalie Smith in Ilford, east London, on 28 December 1934, she once offered a brief summary of her life: "One went to school, one wanted to act, one started to act, one's still acting."

She studied at Oxford High School for Girls and later at the Oxford Playhouse School, which led to a busy apprenticeship.

She used Maggie as her stage name because another Margaret Smith was active in the theatre.

Dame Maggie first appeared on stage at the age of 18 in Twelfth Night and made a name for herself starring in revues as a singer and dancer.

Her talent was spotted by Laurence Olivier, who invited her to join the newly-formed National Theatre Company in London.

There and at the Old Vic she demonstrated her abilities in both tragedy and comedy and listed directors Ingmar Bergman and William Gaskill as important influences.

Success in the film industry

Dame Maggie's abilities were quickly recognised by the film industry and she was initially given several supporting roles.

But she later emerged as a leading star with her performance as the fanatical teacher Jean Brodie in The Prime Of Miss Jean Brodie in 1969, for which she won a best actress Oscar and a BAFTA.

She earned a second Oscar for her role in California Suite in 1978, which won her a best supporting actress trophy, as well as a Golden Globe.

She was made a dame by the late Queen in 1990.

A new generation of fans from Harry Potter and Downton Abbey

Dame Maggie went on to star in Love, Pain And The Whole Damn Thing, The Lonely Passion Of Judith Hearne and Gosford Park, which earned her a sixth Oscar nomination.

But she was introduced to a whole new generation of fans when she played Professor McGonagall in the Harry Potter films and Violet Crawley, the Dowager Countess of Grantham, in Downton Abbey.

"I am deeply grateful for the work in [Harry] Potter and indeed Downton [Abbey] but it wasn't what you'd call satisfying," she told ES Magazine.

"I didn't really feel I was acting in those things."

Her role in the Downton Abbey TV series won her three Emmys, a Golden Globe and four Screen Actors Guild Awards.

Once when she was asked why she took the Harry Potter role she quipped: "Harry Potter is my pension."

A slew of awards

Dame Magie won numerous awards throughout her career, including for her performances in Tea With Mussolini, A Room With A View, A Private Function and The Lonely Passion Of Judith Hearne.

One of her most celebrated roles was in The Lady In The Van, the 2015 adaptation of Alan Bennett's memoirs.

Dame Maggie married fellow actor Robert Stephens in 1967 and they had two sons together before divorcing in 1975. The same year she married the writer Beverley Cross, who died in 1998.

She leaves behind two sons and five grandchildren "who are devastated by the loss of their extraordinary mother and grandmother", her sons said in a statement.