Her children Chris Larkin and Toby Stephens said in a statement she died in hospital on Friday and they were "devastated by the loss of their extraordinary mother and grandmother".

The King and Queen have paid tribute calling her a "national treasure" adding they would remember "with the fondest admiration and affection her many great performances, and her warmth and wit".

Born in Essex in 1934, Dame Maggie became an internationally recognised actress and one of the most versatile, accomplished and meticulous performers of her generation - winning two acting Oscars, several BAFTAs and numerous other awards.

More recently she won a new generation of fans as Violet Crawley, the Dowager Countess of Grantham, in Downton Abbey and playing Professor Minerva McGonagall in the Harry Potter movies.

But she later told ES Magazine: "I am deeply grateful for the work in [Harry] Potter and indeed Downton [Abbey] but it wasn't what you'd call satisfying. I didn't really feel I was acting in those things."

Harry Potter actor Daniel Radcliffe said she was "a fierce intellect, a gloriously sharp tongue, could intimidate and charm in the same instant and was, as everyone will tell you, extremely funny".

JK Rowling simply tweeted: "Somehow I thought she'd live forever. RIP Dame Maggie Smith."

While Emma Watson, who played Hermione Granger throughout the franchise, posted a picture of Dame Maggie holding her face while on the set of one of the films.

She wrote: "When I was younger I had no idea of Maggie's legend... it is only as I've become an adult that I've come to appreciate that I shared the screen with a true definition of greatness... Maggie, there were a lot of male professors and by God you held your own."

Gary Oldman, who also shared the screen with Dame Maggie in several Potter films, described her as the kind of talent that "comes along about every other generation".

The Downton Abbey TV series won her a series of awards - three Emmys, a Golden Globe, and four Screen Actors Guild Awards.

In a statement, her co-star Hugh Bonneville, who played Violet's son Lord Grantham, said: "Anyone who ever shared a scene with Maggie will attest to her sharp eye, sharp wit and formidable talent."

On Instagram Dan Stevens, who played Matthew Crawley, wrote simply: "Truly one of The Greats. RIP" alongside two pictures of his former co-star.

Downton creator Julian Fellowes - who also worked with Dame Maggie on the movie Gosford Park - told Sky News she was "always very kind, very professional, very funny, both in her acting and off the screen. And you never had to explain a line".

Whoopi Goldberg said she felt "lucky" to have worked alongside her in Sister Act, adding she was "one of a kind".

Meanwhile, a message on X from BAFTA said: "Dame Maggie was a legend of British stage and screen, winning five BAFTAs as well as a BAFTA Special Award and BAFTA Fellowship during her highly acclaimed career."

Although she was a tour de force in leading roles on the West End stage, she was equally happy - even during the years of her mega-stardom - to accept supporting roles, particularly in films.

At the National Theatre and Old Vic, she excelled in both tragedy and comedy, moving easily from Shakespeare to Noel Coward, to Restoration comedy to Ibsen.

Even in smaller roles, she could upstage the film "giants". In one film, Richard Burton described her scene-stealing as "grand larceny".

Some of her other best-known movies included: Death On The Nile, Gosford Park, The Best Exotic Marigold Hotel and its sequel, and The Lady In The Van - the adaptation of Alan Bennett's memoirs.

She married fellow actor Robert Stephens in 1967, had two sons who both became actors, and divorced in 1975. The same year she married the writer Beverley Cross, who died in 1998. She was made a Dame in 1990.