A bit strong. You can add “in vain,” if you like.

The London production of “King Lear,” directed by Deborah Warner, was austere, Brechtian and British, with a sly indictment of Blairism. The set was constructed of white, portable panels, and actors carried their chairs on and off the stage. Jackson delivered her opening lines with her back to the audience. The Broadway play as envisioned by the director Sam Gold, however, is lush; the set, a jewel box, with brassy, Trumpian accents. Jackson’s Lear not only faces the audience but plays to us and plays with us. In the opening scene, Lear divides his kingdom among his daughters — “conferring them on younger strengths while we/Unburdened crawl toward death.” Jackson rolls the r’s in “crawl,” stretching the word long and louche, a purring lion, all easy, unstrained dominance that flares into spectacular explosions of rage.

At 82, she does not look whittled, wizened or weathered or any one of those wheezy words we use for old bodies. She does not look diminished — she looks distilled, unwrapped, the long bare branches of her body mesmerizing. “Glenda is so lean, and I don’t just mean that physically,” the actor Elizabeth Marvel, who plays Goneril, told me. “I mean that emotionally, intellectually. All the fat is burned off, and you just have this brilliant diamond core.” Jackson is not the first woman to play Lear, nor does gender enter your mind as you watch her. She herself has spoken of how differences between the sexes fade with age, but her authority has always transcended any notion of gender; it has always felt like law. The first time she played Shakespeare, in 1965, one review was headlined “Ophelia, Prince of Stratford.”

“There aren’t a lot of actors in the world that you can cast in a part like this, who can just enter the room and bring so much power with them,” Gold told me. “They don’t have to work or earn it, they just have it.” What is the source of that power? Jackson is the smallest person on stage, but you won’t notice it — she arrives cascading over the language, dominating it. In this way Jackson gives us the only truly contemporary interpretation of Lear I’ve ever seen, a king whose command relies not on brute might but in the ability to manipulate words. The actor playing Lear must not only embody authority but also slough it off in front of us, almost presenting the aging process brutally sped up. The ritual aspect of this transformation is of particular interest to Gold, who has directed stripped-down interpretations of Shakespeare, including “Othello” in 2016. “Glenda is going to do something very intense, very special, very big,” he said. “She is going to go through something most people don’t go through. You’re all invited. Glenda Jackson is going to endure this, and you’re going to witness it.”

For most of its history, this ritual has been considered too traumatizing for the stage. Shakespeare himself worried the conclusion was too bleak; he appears to have softened it slightly a few years after the play was first put on. Still, for 150 years an adapted version, with a happy ending, was performed. In the kingdom of Lear, there is no consolation. Characters learn to see the truth only after their eyes are gouged out; they learn to love their children only as they mourn them. Lear dies of heartbreak, annihilated, his last line a howl. It is a play of such immensities — of sorrow and language — that it has been described as too big for the stage, a literary achievement and not a dramatic one, or even a natural phenomenon in its own right: a volcano to the essayist Charles Lamb, a hurricane to the poet Samuel Coleridge and to the critic William Hazlitt, the sea: “swelling, chafing, raging, without bound, without hope, without beacon, or anchor.” This is not to mention the deep, dislocating strangeness of the play itself. The improbabilities in the plot alone have kept scholars busy for close to 400 years. It is set in 800 B.C. yet all signs point to the Middle Ages. Lear and the villain, Edmund, never interact. There is an odd lack of stage directions and that superfluous subplot, the story of Gloucester, which just echoes the main action (a father betrayed by his child).

The deepest strangeness of all: None of this matters. Critics have argued that the play is greater for these inconsistencies — more vast, as capricious and real as the world itself.

Lear remains the crowning role of the most powerful actors of their generations. “When you’re younger, Lear doesn’t feel real,” Laurence Olivier once said. “When you get to my age, you are Lear in every nerve of your body.” Most performances follow in the footsteps of Paul Scofield, who played the king as a grizzled military man in the 1962 Peter Brook production, later a film. Ian McKellen put his slant on the role, making Lear a priestly figure; Christopher Plummer played him as a dementia patient.