Possibly because he was 74 when he took the role, Christopher Plummer imagined King Lear to be 84. That should have been a clue: For Plummer, who died Friday at 91, the end of the road was always 10 years off.

But at the time, I assumed he had deliberately chosen to star in Jonathan Miller’s production of the great Shakespeare tragedy as a way of capping his career. Meeting him on three occasions while the show rehearsed in January 2004, I noticed his adolescent panache but also his Lear-like dependency. For one interview, he wore his shirt open past his solar plexus. And yet his wife (she told me) checked his pockets before he left for rehearsal; as I saw for myself, she monitored his menu at dinner after.

If this was to be the end of his acting life, it had, after all, been a long, successful and mostly noble one. His first professional roles, as a teenager, were in French in Montreal; his Broadway debut, in a one-night bomb called “The Starcross Story,” was just a few years later, in 1954. Soon came the leading classical roles in Stratford and New York and London, the sexy ’60s romps and the international fame from what he persisted in calling “The Sound of Mucus” or, more bitingly, “S&M.”

But by “Lear,” that all seemed to be ending. Already gone were the boozing, womanizing, gourmandising and joy-riding of his youth, which had often transpired all at once, at least in the stories he told me about them. In one, set in the mid-50s, during the peak of his bar-crawl days, Bobby Kennedy and Marilyn Monroe were just the bit players.

The main plot was this: After tearing down Third Avenue to get a jump on closing time, he was catapulted from Jason Robards’s motorcycle directly through the door of P.J. Clarke’s and into a seat at precisely his table, where Robards, tumbling into place next to him, promptly looked up and said, “A double martini, please.”

I didn’t believe the story, but it didn’t matter; the performance — we were at the Players Club, among paintings of dead actors — was superb. He even burnished his mischievous sparkle with a faint hint of tears, as if to say that the kind of fun you could have back then was gone, and so was the kind of work. Broadway roles for septuagenarians were almost nonexistent, and who would want him anymore in film?

Though he still hoped to play Prospero and James Tyrone — “actors are not businessmen with hobbies to retire to!” he huffed — he imagined himself potentially reduced to organizing what he not quite disparagingly called “evenings of readings.”

This was, apparently, just another superb performance, because after “King Lear,” and almost straight through to his death, his career never faltered. Instead, it just kept chugging along, except that chugging does not normally net you a seventh Tony nomination (for “Inherit the Wind,” in 2007), two more Emmy nominations, two more Academy Award nominations — and one Oscar win. That win was in 2012, for touchingly underplaying a gay man coming out of the closet at 75. The movie was called “Beginners.”

He could underplay on film because he knew how to play big onstage; he had long since mastered his register and was not afraid of extremes. “Edith Evans taught me the superstition that you never say the last line of the play until opening night,” he explained. “And then you whisper it, you hardly say it all, so that it absolutely screams across the footlights. Of course, those were the days when the audiences knew the words already, so you didn’t have to say them at all, really.”

They were also the days when theaters had footlights. Plummer was perhaps the last of the great actors trained in the pre-Method, pre-academic, pre-movie style. (He didn’t go to drama school; he went on the road.) Especially as his type became rarer and rarer, that made his control of his effects ever more valuable. What he could do with his voice, his hands and even his teeth — in “King Lear,” they seemed to grind independently of his will — was amazing, even if all were tricks.

Which is not to say he ignored character work from the inside out, provided there was an inside. When he was cast as Captain von Trapp in the movie of “The Sound of Music,” he begged the director and screenwriter to improve the role from what it had been onstage: a man so inconsequential, he told me, that “every time he opened his mouth, Mary Martin had another song.”

He did make something more complex out of that empty character; when I said he was a bit creepy in the role, he was delighted. In truth, I found Plummer, for all his charm, a tiny bit creepy himself. Not malevolent, but uncanny: a superannuated genius child like the kind you might find in a horror movie. You had to watch him.

Along with the martinis (and the solicitude of his wife), his fame, which came young, preserved him like an onion. He wrenched tears from audiences longer than perhaps any other modern actor did; if he could, he would no doubt play Lear at his own funeral, except that he was still far too young.