British Actor Maggie Smith Dies Aged 89

Maggie Smith is announced as a nominee for Outstanding Performance by a Female Actor in a Drama Series for "Downton Abbey" as actors Taye Diggs (L) and Busy Philipps announce the nominations for the 19th Annual Screen Actors Guild Awards in West Hollywood, California December 12, 2012.(REUTERS/Jason Redmond)

LONDON (Reuters) -Britain's Maggie Smith, one of the most acclaimed actors of her generation with a career ranging from Shakespeare to Harry Potter and Downton Abbey, has died aged 89, her family said on Friday.

Smith was one of a select few to win the treble of an Oscar, Emmy and Tony during seven decades on stage and screen, becoming a star known for her sharp intelligence and waspish wit.

British Prime Minister Keir Starmer said Smith "introduced us to new worlds with the countless stories she acted over her long career".

"She was beloved by so many for her great talent, becoming a true national treasure whose work will be cherished for generations to come," he said.

After starting on stage in the 1950s, Smith became a fixture at Britain's new National Theatre in the 1960s, working alongside Laurence Olivier, before winning her first Oscar at the end of the decade.

But for many younger fans in the 21st century, she was best-known as Professor McGonagall in all seven "Harry Potter" movies, and the Dowager Countess in the hit TV series "Downton Abbey," a role that seemed tailor-made for an actor known for purse-lipped asides and malicious cracks.

She died in hospital in London early on Friday, her sons Chris Larkin and Toby Stephens said.

"An intensely private person, she was with friends and family at the end," they said in a statement.

Smith's first Academy Award nomination was for her turn playing Desdemona opposite Laurence Olivier's "Othello" in 1965, before winning the Oscar for her role as an Edinburgh schoolmistress in 1969's "“The Prime of Miss Jean Brodie."

She won her second Oscar for her supporting role in the 1978 comedy "“California Suite".

Other critically acclaimed roles included Lady Bracknell in Oscar Wilde's “"The Importance of Being Earnest" on the West End stage, a 92-year-old bitterly fighting senility in Edward Albee's play "“Three Tall Women," and her part in 2001 black comedy movie "Gosford Park."

In 1990 Smith was knighted by Queen Elizabeth and became a Dame.

(Reporting by Sarah Young, Kylie MacLellan and Paul Sandle; Editing by Kate Holton and Hugh Lawson)