Who was that masked man?

In death, great comedians leave behind the sense memory of what made them great -- Jackie Gleason’s sweaty snarl, Milton Berle’s withering look -- but the case of Peter Sellers, another great comedian, is trickier. Even though Sellers has been canonized with his own shelf at my local video store, I have to admit I haven’t thought about him in years. Sellers was a prolific comedic actor and mimic, but he was also an impressionist who failed, in the end, to leave an impression.

But he was interesting for this, and tragic, and now he has gotten a highly entertaining biopic. In “The Life and Death of Peter Sellers,” an HBO original movie airing at 9 Sunday night, Sellers, played by the uncanny Geoffrey Rush, emerges as a lot of things -- an infantile mamma’s boy, an abusive husband and father, an impossible star, a sad clown. Along the way, the movie celebrates the ways in which Sellers managed to channel his kinetic energy into an astounding catalog of characters, including the ones for which he would become best known -- Inspector Clouseau of “The Pink Panther” movies, Dr. Strangelove, even Chauncey Gardiner of “Being There,” in which Sellers, in his second-to-last film, erased all the creative chaos that had come before and made himself perfectly still.

Married four times, Sellers died in 1980 of a heart attack at age 54. By then, he had been miserable for years, evidently, petulant and depressed and given to violence. He wanted to be a leading man but didn’t have the looks; he came to hate the way people associated him with pratfalls. He carried out this quarrel with himself openly, almost as a career, making any number of confusing or unwatchable movies as if to contradict the great ones.

By default, it can seem, all psychological portrayals of comedians arrive at the conclusion that the off-stage neuroses fueled the on-stage magic. But “The Life and Death of Peter Sellers” is saved from this biopic cliche by its tweaking of the form. The movie is not straight biography, and Rush doesn’t just play Sellers. He plays Rush playing Sellers playing other characters in the film. These meta-creations speak directly to the camera about the man Peter Sellers -- the idea being that there was no grounded self, finally, no first person, so Sellers escaped into caricature as a way of connecting with the world.

Or was he just mocking those with whom he knew he was supposed to be connecting? You’re not always sure, though sometimes you are. “Absolute control is a useful thing,” Rush as Sellers playing Stanley Kubrick, who got Sellers to do arguably his best work in “Dr. Strangelove,” says at one point. “Eliminate the personal element and you can get so much more done. This was a realization that Peter Sellers never had to face, because there was no person there to begin with. He was a vessel into which personalities and characters ran like phantoms.”

That somewhat heavy-handed conceit -- that Sellers was nobody so he flailed at being everybody, and therefore somebody -- deflates the movie at times. But “The Life and Death of Peter Sellers” also reverberates with Sellers’ comic mania and libido. It re-creates the swinging London of the 1960s and ‘70s, the setting against which Sellers the star was born. Because his career had no seminal moment, really, the movie is a pastiche of his work (and a pastiche of his libido, for that matter), with the gossipy bits of his life mixed in. We get some of the more eye-opening anecdotes. How, married to his first wife, Anne (Emily Watson), with two young children at home, Sellers bought a flat in London to increase his chances of sleeping with Sophia Loren (Sonia Aquino) during the making of “The Millionairess.”

“Do you still love us?” Sellers’ young daughter asks when he announces he’s leaving the nest to pursue his costar. “Of course I do, sweetheart,” Sellers responds, “just not as much as I love Sophia Loren.”

He never bedded Loren and eventually had to settle for Swedish model Britt Ekland, played in the film as a fun series of giggles and “Oh, Peters” by Charlize Theron. John Lithgow is strong as Blake Edwards, the director with whom Sellers warred through half a dozen “Pink Panther” movies, as are Stanley Tucci as Kubrick and Stephen Fry as Maurice Woodruff, the fortuneteller Sellers consulted for life and career advice.

Everybody in the cast seems imbued with the Sellers sense of play; you get the feeling that director Stephen Hopkins mostly got out of his actors’ way. Lithgow, particularly, has a lot of fun as the turtleneck-wearing Edwards, who was both the bane of Sellers’ existence and the man who delivered him to his largest audience; and Miriam Margolyes as Sellers’ mother, Peg, is formidably funny.

Based on the book “The Life and Death of Peter Sellers” by British author Roger Lewis, the movie skips over Sellers’ childhood (he was born in England to parents who performed in music hall revue shows) and picks up at the point where Sellers is leaving “The Goon Show” on BBC Radio to do movies.

We see the creepy relationship that endured into middle age between Sellers and Peg. “Both channels,” she murmurs with self-satisfaction, watching British TV coverage of the near-fatal heart attack Sellers suffered while honeymooning in Hollywood with Ekland.

We see how Sellers invented Clouseau on a drunken flight to the set of “The Pink Panther,” going into the lavatory to shave off his beard but leaving the mustache. “Are you Peter Sellers?” the man in the seat next to him asks. “Not today,” Sellers responds.

The film has the rhythm of the manic-depressive, all crazy highs and paralyzing lows. Sellers worked in Hollywood, of course (United Artists released “The Pink Panther” movies), but much of the film, like his career, is set against the estates he owned in England and Switzerland and movie sets in Rome. Not that Hopkins succeeds in making the shifting landscapes clear; a general feeling of Sellers-like dislocation prevails. This may be true to the movie’s subject but doesn’t always work to lift Sellers up to icon status.

And yet the fact that he wasn’t careful about his career can make Sellers seem, looking back, more noble. This is what Milos Forman tried to do with the Andy Kaufman mystique in the misshapen “Man on the Moon,” but Kaufman’s persona and body of work were flightier and thinner. Kaufman was a performer, Sellers was a star -- a star who staggered and lurched through a long career.

“You know how they clean theaters now?” Sellers is heard saying in the film. “They put on one of my films. It’s so much easier to hoover between the empty seats.”

He was referring to box-office duds like the 1972 hospital comedy “Where Does It Hurt?” The movie presents “Being There,” in which he played a gardener with no self-identity, as the coda of Sellers’ career, a last great stab at actorly immortality.

The role earned Sellers an Academy Award nomination. There would be two more films, both slapstick comedies, “The Fiendish Plot of Dr. Fu Manchu” and “The Trail of the Pink Panther,” for which Edwards used outtakes and unused footage from previous “Panther” movies.

This is where “The Life and Death of Peter Sellers” leaves its subject -- outside a chalet in Switzerland, Sellers catatonic in the snow, unable go inside for a meeting with Edwards. Out there, frozen. The ending is appropriate if sad, difficult and strangely moving. Very Sellers.

*

‘The Life and Death of Peter Sellers’

Where: HBO

When: 9 p.m. Sunday

Rating: TV-MA (may be unsuitable for children under age 17)

Geoffrey Rush...Peter Sellers

Charlize Theron...Britt Ekland

Emily Watson...Anne Sellers

John Lithgow...Blake Edwards

Miriam Margolyes...Peg Sellers

Stanley Tucci...Stanley Kubrick

Sonia Aquino...Sophia Loren

Stephen Fry...Maurice Woodruff

Executive producers Freddy DeMann, George Faber, Charles Pattison, David M. Thompson. Director Stephen Hopkins. Teleplay Christopher Markus and Stephen McFeely.