Ned Kelly has assumed a saint-like status – somewhere between Robin Hood and Che Guevara – in the 135 years since he was hanged, aged 25, in Melbourne. Rather like a holy statue, his story has been rubbed for luck so often that its original shape and attributes have become a bit blurred. Religions have been founded on less.

So the location of Imagining Ned, a major new exhibition pulling together art, artefacts and films inspired by the noble outlaw / murderous criminal, is hardly a surprise. Bendigo Art Gallery in central Victoria is at the edge of what is now known, in the tourist brochures, as Kelly Country, a region that does a brisk trade in Kelly gewgaws and re-enactment weekends. In May, a musical based on Kelly’s life, Ned, will premiere at Bendigo’s new Ulumbarra theatre.

As outlaws go, the Victorian horse rustler, bank robber, distributor of funds to the poor, cop killer and firebrand anti-establishmentarian had bags of charisma and was a beacon of defiance and excitement for the downtrodden, mainly Irish, farmers and small-town strugglers. Ned’s appeal still resonates today with anyone who identifies with the “disenfranchised outsider and the underclass”, says Bendigo’s director , Karen Quinlan. Like the helmet, he’s “strong, enduring, symbolic,” she adds, careful to emphasise the Bendigo show refrains from taking sides.

The exhibition includes many of the famous paintings and sketches created by Sidney Nolan between the 1940s and the artist’s death in 1992; his half-man-half–letterbox-head rendition of Ned as an iron-clad hero stemmed from tales the young Nolan was told by his grandfather, one of the policeman who chased Kelly and his gang across wild country.

Alongside Nolan’s works are pieces by his contemporaries Arthur Boyd and Albert Tucker (the latter called Nolan Ned), sketches by the older artist Norman Lindsay, and works by several contemporary names including Juan Davila, Adam Cullen and Liam Benson. There is also a painting by Gija man Freddie Timms from the eastern Kimberley, an Indigenous people whose dreaming creation story has included Kelly for at least the past 70 years.

Works by Chinese born Guan Wei reimagine Kelly as a commando-style hero in a much larger landscape, as in Ned Kelly Encounters the Troopers in the Mystic Mountains (2003), a large ink work on rice paper. Thai born Vipoo Srivilasa sees him in Networking (2013) as a blue and white china helmeted figurine, mobile phone in hand, standing on a base decorated with social media symbols.

Imagining Ned also includes Kelly’s death mask, the Snider Enfield rifle he wielded in his bank hold-ups and hostage taking, and his famous iron armour and helmet, made from plough blades. He and the gang wore these in the last shoot-out with police at Glenrowan northern Victoria – and Kelly’s chimney like head protection looks nothing like Nolan’s instantly recognisable horizontal box.

There’s the famous Jerilderie letter, from the State Library of Victoria collection, renowned for its wildly poetic language and a description of the police as “a parcel of big ugly fat-necked wombat headed, big bellied, magpie legged, narrow hipped, splay-footed sons of Irish bailiffs or English landlords.”

It’s also an 8,000 word manifesto dictated by Kelly to fellow gang member Joe Byrne in 1879. Alongside cataloguing the police persecution meted out to Kelly and his family and justifying the killing of three policemen in a forest ambush as self defence, the letter demanded justice for the poor and downtrodden.

It was this political dimension to Kelly’s deeds and utterances that made him a folk hero in his lifetime, according to the exhibition’s co-curators, Leanne Fitzgibbon and Tansy Curtain. “It wasn’t just about hurting the rich and giving to the poor,” says Curtain, “he had these great ideas, in the Jerilderie letter in particular, of starting a new republic for Australians. He talked about the oppressed cultures within Australia and of overthrowing those oppressors.”

There’s also a story of martyrdom in his actions, adds Fitzgibbon: “He really wanted his views to be heard, so instead of disappearing into the outback when things went bad, he made the point that he wanted to stay and sought to have the letter published.”

The letter was actually suppressed for 50 years. Also banned was a 1906 film by Charles Tait, The Story of the Kelly Gang, made 26 years after Ned’s death and inscribed in the Unesco memory of the world register as the world’s first and still-surviving full-length feature film. Although shown around the country it was excluded from the state’s north-east around Benalla and Greta, the Kelly’s family powerbase and home to many of his most dedicated supporters.

His support was strong in the metropolis of Melbourne, too. Fitzgibbon shows me the petition of more than 30,000 signatures gathered in 1880 pleading for Kelly’s life. There are echoes, she says, of the current Australia-Indonesia stand-off over the scheduled execution of convicted drug smugglers Andrew Chan and Myuran Sukumaran.

Only fragments of the Tait film remain, amounting to about 17 minutes but they are a fascinating addition to the show and probably more accurate than many subsequent cinematic and literary efforts. There are stills from Ned Kelly, the 2003 Heath Ledger vehicle which turned the modest death toll at his capture into a wholesale slaughter, and the Mick Jagger film from 1970, directed by Tony Richardson. The latter was full of lilting ballads and also gave Kelly a very fictional wife. (Peter Carey’s novel The True History of the Kelly Gang which won him the Booker Prize in 2001 also supplied a fictional daughter.)

Lurid tales of the Kelly Gang circulated in print during their lifetime and a collection of comics, penny dreadfuls and pulp novels give a taste of what was, from the start, a very visual story. They include a version of the drama in the New York Detective Library of 1892 and an even earlier and more fanciful description in an 1883 edition of the French magazine Journal de Voyages et Aventures de Terre et de Mer. Its illustrations of the helmeted Kelly are distinctly Gallic (including horns) and his sister Kate sports a Musketeer’s plumed hat.

From an everyman to the man who would be king, the exhibition is suffused with a sense of a life gone wrong and has all the ingredients of an A-grade tragic hero tale. Bendigo artist Clayton Tremlett has taken the what-might-have-been theme as the basis for his self-portrait linocut, Self-Portrait as Ned Kelly Aged Fifty. Sporting a bushy beard and lined cheeks, it’s a meditation on how Kelly would have fared had he lived.

The subtitle of the piece – There’s a Ned in every crowd – points to the ambivalence at the heart of Kelly’s story: is he Ned the champion of the oppressed or Ned the violent criminal? And had he lived, would Kelly have been a leader who stayed true to his democratic impulses or would he have sold out? We prefer the idea of the man in the iron mask to the man with feet of clay.
• Imagining Ned is at Bendigo Art Gallery until 28 June