“She always looks so extreme,” a fellow teacher notes of Maggie Smith’s trademark rigidity in “The Prime of Miss Jean Brodie” (1969), putting her finger on the straight-laced, nose-high haughter audience where more than half enjoyed for years. century.

Jean Brodie, a shrill and tragically short-sighted instructor at a school full of impressionable girls, proved to be the defining factor of the English stage legend’s film career, so much so that her strict but caring Harry Potter character, Deputy Headmistress Minerva McGonagall would be the same martinet, hampered by decades of disappointment. (Kids who grew up on JK Rowling’s adaptations will definitely appreciate “Prime” when they’re older.)

That doesn’t mean she was never better. In fact, Smith, who died Friday, never had a bad performance, and just as fine wines improve with age, so too does the legendary actor’s caustic brand of vinegar, which became the most delicious ingredient in her career as the devastating widow of “ Downton Abbey.”

On the contrary, playing the self-absorbed Miss Brodie accentuated so many of Smith’s strengths – myopic arrogance, precise comic timing and the despite-soothing impression that something essential had escaped her characters earlier in life – that the Oscar-winning performance featured in virtually every subsequent movie echoed. screen part.

It’s there in Augusta, the strikingly manipulative old maid who constantly makes herself the center of attention in “Travels With My Aunt” (an Oscar-nominated role she inherited from Katharine Hepburn, who was too old to do the flashback scenes). to play). And it flares up in ‘Murder by Death’, ‘Death on the Nile’ and ‘Evil Under the Sun’, three brutal mysteries in locked rooms in which Smith’s wry delivery is inevitably fatal.

Among her gifts, Smith wielded sarcasm as a deadly weapon. She had knocked opponents down with a flicker of a stare or laid them low with the gymnastic range of her voice, which went from a switchblade-like whisper to a high-pitched, nasal harpoon. She won her second Oscar before losing one in “California Suite,” in which she played an insecure movie star married to a bisexual ex-actor (Michael Caine). Her imperious bons-mots come through easily in that film, though she will break your heart when she looks into her husband’s eyes and pleads, “Just let me be tonight.”

On stage she could hold her own opposite Laurence Olivier, as her smoldering Desdemona demonstrates in “Othello” – just one of many roles she played for London’s National Theater. In Roger Michell’s delightful “Tea With the Dames,” Smith sits alongside Judi Dench, Eileen Atkins and Olivier’s widow, Joan Plowright, who acknowledges that her natural husband was intimidated by Smith.

Smith and Olivier appeared together in several productions, including the Restoration comedy ‘The Recruiting Officer’ and Henrik Ibsen’s ‘The Master Builder’. But it was on “Othello” that he dealt her a particularly hard blow on stage. “It was the only time I saw stars at the National Theatre,” joked Smith, who was known for being as smart (and salty) in person as so many of her characters. When she received her honorary title, she was told that the title did not have to change anything: “You can still curse.”

Apart from the Harry Potter films – in which the wings were packed with a Who’s Who of British actors – she avoided franchises and instead devoted herself to small productions where she could make a big impression, such as ‘The Best Exotic Marigold Hotel’ (a chance to reunite with “A Room With a View” co-star Dench) and last year’s “The Miracle Club.”

It’s not a perfect comparison, but her characters seemed to grow richer as her career progressed, to the point that the aristocrat she plays in “Gosford Park” (a trial run for the Violet Crawley character in “Downton Abbey”) seems anything but indifferent to the feelings of others. “It must be so disappointing for something like this to flop,” she tells an American film producer (Bob Balaban), later insisting, “I don’t have a snobbish bone in my body.”

But snobbery was Smith’s specialty, which she used with the precision of a sniper. “Vulgarity is no substitute for humor,” she said on “Downtown Abbey.” She was so consistently caustic in that series that if that character thawed for even a moment, those around her might ask, “Did you change your pills?”

Even when portraying working-class characters, such as the pastor’s wife she played in “Bed Among the Lentils,” she showed an instinct for the rightly placed insult. That piercing one-woman show — an hour-long televised monologue written by Alan Bennett, whose “The Lady in the Van” gave Smith one of her indelible final roles — reveals the kind of regret that so often went unspoken in the performances from Smith.

“Around the age of fifty I was ready to become a great woman,” notes Mrs. Vicar, and we are reminded again of Miss Jean Brodie: how the tears welled up in her eyes during that extraordinary Italian slide show she gives her lesson, and we must understand what she wants most for her “gels” (as Miss Brodie pronounces it) is that they avoid the mistakes of her own youth.

“I expected to live until I was fifty,” an incredulous Miss Brodie tells the young Judas who betrays her at the end of the film. While that character’s window closed much earlier, Smith’s continued for decades and entertained audiences until the age of 89.