Shirley MacLaine: Tough at the top

"You Americans," murmurs the Dowager Countess Violet Grantham, a grim vision in black shawl, marcelled hair and the expression of a constipated pug, "never understand the importance of tradition." "Yes we do," snaps Martha Levinson, her rival matriarch in a hat like a saucepan. "We just don't give it power over us. Maybe you should think about letting go of its hand…"

Downton Abbey, the 21st century's supercharged Upstairs Downstairs, is upon us again. And the most awaited scenes of the third series, which airs this month, are between Maggie Smith as the Earl of Grantham's saurian mama, and Shirley MacLaine playing lovely Lady Cora's vulgar millionairess mother Martha. P G Wodehouse's line about aunts calling to each other in the spring "like mastodons bellowing across a primeval swamp" comes to mind, as the antique ladies square up to each other – Lady Crawley a living sigh of regret for the past, Mrs Levinson a breezy embodiment of optimism for the Jazz Age future.

Maggie Smith's mask of disapproval and her toxic put-downs of arrivistes are the strongest reasons for watching the show. It would take an actress of unearthly confidence to climb into the ring with her. But as Julian Fellowes, the originator of the series, has admitted, although it took a little time for her "to adjust to the style and rhythm of the language", they were dead lucky to get Shirley MacLaine.

For she is Hollywood royalty, no question. At 78, she can boast a 59-year career, a Best Actress Oscar (on her fifth nomination), four Golden Globes and, this year, the American Film Institute's Lifetime Achievement Award, than which there is no higher accolade. She's been directed by Alfred Hitchcock, William Wyler, Don Siegel and Richard Attenborough. She has acted with Frank Sinatra, Jack Lemmon, Jack Nicholson, Meryl Streep, Clint Eastwood and Anne Bancroft. In an apotheosis of Hollywood narcissism, she has played herself on TV in Out on a Limb. There is, needless to say, a star bearing her name on the Hollywood Walk of Fame.

Not everything in Ms MacLaine's life, however, has won applause and global approval. From early days, she's shown a remarkable ability to get up people's noses. She has a reputation as a tough bunny. Sometimes she has seemed typecast as a tart-without-much-of-a-heart, from Irma La Douce to Two Mules for Sister Sara. "It's hard to feel much warmth for her," said Don Siegel, who directed the latter film." She's too unfeminine and has too much balls. She's very, very hard." Anthony Hopkins, who worked beside her in A Change of Seasons, called her "the most obnoxious actress I have ever worked with".

One reason may be the memory of the time she sued a studio and won. Offered a part by 20th Century Fox in a film that was cancelled, she was offered a lesser role in another film so that the studio wouldn't have to pay her off. She took Fox to the Supreme Court of California in 1970 – and won. Hollywood doesn't forgive such treatment. Another reason may be that she has always contrived to run a secondary career, made up of autobiographical books, explorations of mysticism, TV shows (Shirley's World) and political activism. Her enthralment by Eastern mysticism, though doubtless sincere, seemed earnest to an irritating degree in books such as The Camino, which took her on a "journey of the spirit", through several past lives to the origins of the universe.

Her actual past life began in Richmond, Virginia, where she was born Shirley MacLean Beaty on 24 April 1934. Her father was a psychology professor, a real estate agent and an alcoholic. "He'd come home drunk," recalled MacLaine, "set something on fire, leave again until the wee hours, then return and sleep till noon." Her mother Kathlyn was a Canadian drama teacher. The parents raised her and her younger brother Warren as Baptists, and passed on, obliquely, their dreams of stardom. "Warren and I might have believed we were not from a show-business family," she wrote later, "but because we both lived out the unfulfilled fantasies of our parents, I think we had a greater inspirational motivation than the Barrymores or the Redgraves."

Her mother enrolled her in ballet classes where, because she was the tallest in class, she was always given boys' roles. While still at high school, she went to New York City at 18 to try acting on Broadway. After graduating, she returned and struck it lucky in the stage version of The Pajama Game, when the actress she was understudying broke her ankle. Hal Wallis, the film producer, saw her in the role and signed her to Paramount.

It was a meteoric rise for the tall, gamine redhead with the wide mouth and the chirpily sexy demeanour. By 21, she had made her debut in The Trouble with Harry, Alfred Hitchcock's worst film, and won a Golden Globe as New Star of the Year. By 23, she'd picked up her first Oscar nomination for playing a small-town tart in Vincente Minnelli's Some Came Running.

Her best role was in Billy Wilder's The Apartment (1960). A mature 25, she played Fran Kubelik, the lift operator in the company building where Jack Lemmon drudges, renting out his flat to after-work lotharios. When Fran – uniformed, pert and pixie-haired, the only sign of life among the corporate minions – is romanced, then dumped, by Lemmon's boss (Fred MacMurray), she attempts suicide in the apartment, and is rescued by Lemmon who falls for her vulnerable resilience. It was a tough act, balancing comedy, romance and near-tragedy, but MacLaine pulled it off, bringing a pre-feminist sass to the film's final line, "Shut up and deal".

Her relationship with her famous younger brother was always problematic. When in 1965 Beatty read the script of Bonnie and Clyde, and decided he wanted to produce it, he wanted Shirley to play Bonnie (against, amazingly, Bob Dylan as Clyde). But when he bought the rights, he decided to play Clyde himself and Shirley was dropped. "It would have been adding incest to injury," she remarked. They didn't speak to each other for years – apparently because he disapproved of her husband Steve Parker, but also because he objected to people thinking he owed his career to her. "I only know what I read in the papers about Warren," she said. "I've tried to reach out to him, but he just doesn't seem to want to communicate with me." She was funny, however, about his reputation as a demon lover. "I'd love to do a kissing scene with him," she said, "just to see what all the fuss is about."

As David Thomson avers in his New Biographical Dictionary of Film, in the 1960s her choice of films seemed "increasingly casual and mistaken… she needed more ambitious parts and more implacable directors than were generally available". As the movies became lamer, her politicking became more visible: she was a high-profile fundraiser and organiser of George McGovern's presidential campaign in 1972. A major return to form, however, saw her carry off the 1984 Best Actress Oscar for Terms of Endearment, and an endearing role as Carrie Francis's mother, Debbie Reynolds, in Postcards from the Edge.

In the past decade, her filmic ambition has been to play Louise Brooks, the silent-movie actress with the helmet-like hairstyle which could be seen as an avatar of the MacLaine look. But her acting has been increasingly eclipsed by her public pronouncements – especially on New Age mysticism (her movie roles tend, coincidentally, towards mystics) and on UFOs, about which she is a soi-disant authority. In 2007, she published Sage-ing While Age-ing, which described her encounters with extraterrestrials.

An 18-carat original, and a once-considerable actress, she now occupies the role of a monstre sacré, who could say or do anything. How one would love to have been a fly on the wall at the filming of Downton Abbey, as the visionary MacLaine "took a little time to adjust" to the down-to-earth reality of filming a historical soap opera in rainy England, under the beady eye of her non-mystical contemporary, Maggie Smith.

A Life In Brief

Born: Shirley MacLean Beaty, 24 April 1934, Richmond, Virginia, US.

Family: Father Ira Beaty, a psychology professor and school administrator; mother Kathlyn Corinne, a drama teacher. One brother, Warren Beatty. Married to businessman Steve Parker until their divorce in 1982. One daughter, Sachi.

Career: Made her film debut in The Trouble with Harry in 1955. Nominated five times for a Best Actress Oscar before winning one for Terms of Endearment in 1984.

She says: "I wasn't afraid of getting old, because I was never a great beauty. I was never a sex symbol. I wasn't interested in my stature as a star. Ever. I was just interested in great parts."

They say: "She was the most obnoxious actress I have ever worked with." Anthony Hopkins