While on the Continent, he had made a pilgrimage to Aix-en-Provence and the hallowed studio of Paul Cezanne, who died in 1906 shortly before becoming a proto-modernist idol to generations of artists.

Smart had also studied under renowned Cubist painter and sculptor Fernand Leger in Paris.

Through these and other experiences overseas, he was able to build on what he had learned from acclaimed Adelaide modernist Dorrit Black about the construction of a painting while enrolled at the South Australian School of Arts and Crafts.

In addition, Smart had spent time with fellow artist friends on the islands of Ischia and Procida, off the coast of Naples, cultivating a lifelong love of Italy, a country to which he would relocate permanently in 1964.

During those convivial, carefree months, he returned to the mainland regularly to take in the treasures of classical antiquity at the National Archaeological Museum.

Now, back on home soil and with much to prove, the 30-year-old was motivated to create a picture that would synthesise, perhaps even reconcile, the two quite divergent traditions he felt increasingly invested in.

These were, firstly, the formal preoccupations of modernism, both French and British, and, secondly, the classically inspired, narrative-led frescoes and altarpieces of the Quattrocento, or fifteenth-century Italy, in particular those by Smart's idol, the painter and mathematician Piero della Francesca.

But the artist needed novel source material, so took himself off to Wallaroo on the Yorke Peninsula to sketch and make watercolour studies in and around the former copper mining town.

In the catalogue accompanying the National Gallery of Australia's summer exhibition, Jeffrey Smart, which opens December 11, co-curator Dr Deborah Hart describes Wallaroo as "an evocation of being and becoming, held in equilibrium".

The painting shows, at left, two young men carrying a small boat ashore, their figures answered at right by two pink posts embedded in rock-strewn sand. Beyond the beach is a sparse landscape, both man-made and natural, whose strong contours and surreal arrangement call to mind a stage set.

Yet Smart's largest easel painting at the time, didn't come easily.

"Wallaroo was a huge struggle for Jeffrey - he finished it, wasn't happy with it and so repainted it from scratch," Hart says by Zoom during a break from installing the show.

"And then it won the 1951 Commonwealth Jubilee Art Prize."

Smart received the good news while dining with Nora Heysen in Sydney, where he had relocated after submitting the work.

"He was struggling financially and the fact he had won 500 pounds meant a lot to him practically and emotionally," she says.

For Hart, the painting's composition underscores Smart's interest in the "bold shapes" and "underlying geometry" of modernist abstraction, while its sense of harmony and balance speaks to his burgeoning fascination with classicism.

"The composition foretells a lot of things that were to follow," Hart says.

"He really nailed it with those two balletic figures - there's a feeling of intimacy and longing there, of something partially suppressed."

She has a point. In his 1996 autobiography Not Quite Straight, Smart recalled growing up gay in Adelaide had left him feeling like a "grotesque joke", in 2003 telling the present writer: "In my generation it was such a beastly thing to be, and so difficult ... I had nice, ordinary parents who didn't understand these freaky things."

Smart would become one of the most significant Australian painters of the later 20th century.

He gained widespread recognition for his exquisitely rendered urban and industrial landscapes, often featuring one or more diminutive figures seemingly dwarfed by their surrounding environment.

Holding his first solo show in Melbourne in 1944, opened by Robert Menzies, Smart exhibited for six decades, including in London and Rome, and his work can be found in the collection of the Metropolitan Museum of Art, New York alongside every major public gallery in Australia.

Wallaroo, which entered the national collection in 1959, is one of 130 paintings and works on paper to go on display in Canberra in what is the most comprehensive evaluation of Smart's career yet.

For Hart and co-curator Dr Rebecca Edwards, part of the fun of putting together such a show is being able to shine a scholarly light on some of Smart's lesser known paintings.

One is Strange Street from 1955, a 30cm x 40cm panel depicting one marble figure among a serene garden of classical statues coming to life, as if about to leap off his plinth and onto the lawn.

"Because it's one of the smallest paintings in the show, you could easily overlook it but it has such a surprising palette - the pink and the red pop against each other," Edwards says.

"And then there's that weird imagery of the figure almost dancing off the plinth, which is fantastic. It's such a concentrated little work," she says.

"There's a surreal, uncanny undertone to Strange Street," Hart muses. "It's almost like something out of a Peter Greenaway film."

The painting doffs its cap to the classicising, 'empty piazza' landscapes of Italian Giorgio de Chirico, for whom Smart felt great affinity.

Yet it also points to his interest in the formal qualities and geometric possibilities of the stuff of contemporary life - in this case, a row of square billboards in block colours facing off against the carved figures.

When Smart made this painting, he was living in Bondi and teaching part-time at The King's School in Parramatta.

In addition, he was playing art-loving Phidias on ABC Radio's children's program The Argonauts Club, a role he carried to television in 1956 for The Children's Hour.

Throughout this period, Smart was trying to save money to get himself back to Italy.

Edwards notes the 1950s was a time of difficulty and experimentation for him. He felt increasingly isolated for sticking to his realist guns when many of his peers were fully embracing abstraction and, later, abstract expressionism.

"He didn't produce a large number of paintings in this decade but he painted 10 murals, which is actually incredibly productive because they're huge and quite labour-intensive," she says.

"It's a completely overlooked part of Smart's practice as an artist."

While few traces of these projects remain, documentation in the exhibition catalogue reveals Smart to be an intelligent muralist who understood such works must intimately relate to the space in which they're situated, and that their decorative appeal is at least as important as their narrative function.

"If you look at some of the smaller paintings he's making at this time, there's a mural aesthetic to them in that there are clear outlines and silhouettes are pushed to the front," Edwards says.

In 1961, Smart was included in a survey show of Australian painting at the Whitechapel Gallery in London.

The next year he made what is arguably his best known painting, Cahill Expressway, featuring its famous one-armed bald man in a blue suit, which was acquired by the National Gallery of Victoria in 1963.

That same year he was curated into Australian Painting: Colonial, Impressionist, Contemporary at London's Tate Gallery. Things were looking up.

Following a stint teaching life drawing at East Sydney Technical College, Smart departed Sydney for London via Naples in December 1963.

A special focus of this exhibition is his period in Rome between 1964 and 1970, when he purchased Posticcia Nuova, a property in Pieve a Presciano, Tuscany. He would live there the rest of his life.

"In Rome, he's still finding himself and in the works of that period we see a tension between old and new," Hart says.

"You've got the Italian nonna standing in a flea market and she reappears in different incarnations."

"They're recurring characters, in a way," Edwards chimes in.

"And these paintings have an Italian cinema feeling to them - Deborah writes about Vittorio de Sica's Bicycle Thieves in the catalogue. It's all sharp spotlights and figures in dramatic black looking out from balconies."

Rome is really where Smart began to consolidate what he was about and where many of his familiar motifs first appeared.

"These pictures are quite small but show him enjoying Rome, from the crumbling ruins of the city to all the new technologies emerging at the same time," Edwards says.

"Rome, and indeed Italy, is undergoing a major building program and there's a clash between old and new. A lot of the 'new' would have seemed surreal and strange at the time and that comes through in the paintings."

Here is where we begin to see radar dishes and control towers, high-rise identikit apartment blocks in pastel tones and the brightly coloured signs and markings of the autostrada.

The attention to detail is as striking as the composition is finely calibrated.

In Smart's vision, Rome and beyond becomes a transitional zone people move through.

"The fringes of a city, the edges and the bits that are ugly are what Jeffrey was interested in," Edwards says.

"He had an eye for overlooked details and an ability to turn the mundane into the beautiful."

"Even early on in Adelaide he was interested in rubble and broken things on the edges," Hart points out.

"Part of that comes from his reading of poetry and T.S. Eliot in particular. Jeffrey looked quite closely at the imagery in Eliot's work, especially The Waste Land."

As an artist, Smart travelled widely, constantly seeking new visual input.

"He just loved to look at other artists' work and analyse how they constructed their paintings," Hart says.

But what is Jeffrey Smart's art actually about? Turning to the artist himself is no help as he was famously disinterested in what his works 'meant', preferring to describe them in purely formal terms.

"My main concern always is the geometry, the structure of the painting," is how he once put it.

"Because of the way he includes these recurring figures, it's tempting to see them as actors in a TV show or a stage play but there's never any plot," Edwards says.

"There's never anything to actually connect them, so you have to invent your own narrative. They are in a play without a script."

"He liked open-endedness," Hart adds. "So they're really more akin to poetry - to a haiku, even - than prose because you're never going to get that straightforward linear narrative."

She met Smart, who died in Italy in 2013 aged 91, several times.

She recalls his dry sense of humour during a visit to the gallery in 2005 to inspect some paintings being gifted to the national collection.

"He was self-effacing and also very engaging," she says. "I remember him talking about music and poetry and literature - he was a consummate reader."

By then, Smart was a household name and exhausted by it.

Tasked with taking the great man to visit some of the national capital's other cultural institutions, Hart helped him into her car, only to have her charge turn and say: "Can you please just give me a tour of Canberra's blossom trees?"

Hart was unsure where to go afterwards for lunch.

"I took him to the inner-north suburb of Braddon, which back then certainly wasn't the foodie hub it is now," she laughs.

"We ended up sitting in a cafe opposite a car yard and I thought, oh well, it's kind of appropriate for Jeffrey!"

Jeffrey Smart is at the National Gallery of Australia from December 11, 2021 to May 15, 2022. nga.gov.au

Australian Associated Press