The notorious, armor-clad, 19th-century Australian bushranger (slang for rural outlaw) Ned Kelly had previously been portrayed onscreen by Mick Jagger (“Ned Kelly,” 1970) and by Heath Ledger (“Ned Kelly,” 2003). Neither of those films was particularly memorable. Now, here comes British rising star George MacKay, the long-faced lead actor in “1917,” to sparklingly bring the character to life in what turns out to be the best, by far, of the three attempts to tell the story.

But let’s start with an important point: The beautiful and occasionally brutal film, from Australian director Justin Kurzel, bearing the much longer title “True History of the Kelly Gang,” is not a “true history.” Based on the Booker Prize-winning 2000 novel by Peter Carey, it, like the book, is a dramatic mix of fact and fiction that tells a fanciful version of the short life of Kelly from the age of 12 (terrifically played by Australian newcomer Orlando Schwerdt) to his final date with destiny 13 years later.

I won’t attempt to speculate what’s true here and what isn’t, because since the film is making no claims to it, it doesn’t make any difference. Besides, what’s up on the screen is both riveting and entertaining.

Young Ned is first met growing up in a tin shack in a rural town north of Melbourne, the oldest of his siblings, with his mum, Ellen (Essie Davis), and dad, Red, all of them just eking by. Red (Ben Corbett) was a no-count loser who didn’t provide for his family. Ellen, much to Red’s consternation, earned money by selling her body to various male visitors, including the strapping but dastardly Sgt. O’Neil (Charlie Hunnam).

After Red is removed from the story, Ellen, hoping to give Ned something of a future, works out a deal with an old friend, the smiling, rough and tumble scoundrel Harry Power (Russell Crowe in an extended, scene-stealing cameo), who takes the lad out on the road to teach him the ways of the world, which include keeping a journal “to write your own history” and how to kill people.

Every performance in the film’s first 40 minutes is right on the mark (Crowe even gets to sing!). But it’s at that point, 10 years later in the story, that MacKay appears, bent backward, his head disconcertingly upside down, his adult Ned Kelly preparing for a bare-knuckle barroom fight, just before heading back home to his mum and grown siblings with hopes of becoming a farmer.

But that hope doesn’t materialize, and we know that part is true, that Ned will end up embracing a life of crime, due to a variety of reasons, people and circumstances. It’s then that the film starts introducing many more characters. Of note are George King (the amazing Marlon Williams), the much-younger man - and cad - who is about to marry Ned’s unbalanced mum, and who is training Ned’s brothers to become thieves; the charming but heinous Constable Fitzpatrick (Nicholas Hoult), whose behavior eventually goes unhinged; and Mary Hearn (Thomasin McKenzie), a sweet young woman working at a local brothel.

It would be simplest to say that this is an Australian art house Western, but it’s chock full of cinematic and storytelling ingredients that pull it up above that category. It’s about bad things happening to good people, and the revenge being sought because it of; it gets into people who are so driven by their goals, they start losing their marbles; and it offers explanations of why the bushrangers who became known as the Kelly Gang started donning dresses and armor before going into action.

One outstanding visual highlight of the film occurs near the end, when the law is closing in on the gang, and the screen erupts in an eerie and bizarrely and beautifully photographed nighttime gunfight. But even that long sequence can’t hold a candle to the bigger-than-life, make that gigantic, performance by George MacKay. He’s been at his craft for quite a while, and he’s now, finally, a star in the making.

“True History of the Kelly Gang” will be available on most digital and cable platforms beginning April 24.

Ed Symkus can be reached at esymkus@rcn.com.

“True History of the Kelly Gang”
Written by Shaun Grant; directed by Justin Kurzel
With George MacKay, Essie Davis, Nicholas Holt, Russell Crowe, Charlie Hunnam
Rated R