In medieval Italy, a wealthy young man called Giovanni di Pietro di Bernardone, son of a silk merchant, threw off his worldly identity to become the wandering preacher known to history as Francis of Assisi. Happy in his poverty, communing with nature, speaking to birds, praising Brother Sun and Sister Moon, his radical, joyous version of Christianity challenged a church that had become a system of power and wealth.
You don’t need to believe to believe in Saint Francis. Francis was the real thing, as innocent and poetic as his portraits, to judge by a letter he wrote to his friend Brother Leo that’s on display in the National Gallery’s enraptured exhibition about this inspiring figure. And his vision is as urgent as it was 800 years ago, seen in surprising finds including a medieval feminist fresco of Poor Clares, as the female Franciscan order was called, and a silvered horn given to Francis as a symbol of peace by Sultan al-Malik al-Kamil.
Saint Francis of Assisi is co-curated by the National Gallery’s director, Gabriele Finaldi. Considering his job, he’s refreshingly free from art snobbery. The show celebrates the sentimentality and artistic beauty Saint Francis inspires: as if you’d wandered into a baroque church in Naples where great art hovers amid candles, incense and grisly effigies. It includes a Marvel comic entitled Francis Brother of the Universe among paintings by El Greco and Fra Angelico. At first I thought: “What desperate stuff.” And do we really need to be greeted by an Antony Gormley statue spreading its arms and gazing heavenward? Yet it’s a valid inclusion, because it replicates the stance of the enraptured saint in a painting by Bellini.
The exhibition includes actual relics. The brown sackcloth habit and hempen belt that Francis is said to have worn are here, lent by the Basilica of Santa Croce in Florence. This matted fabric is juxtaposed with a 1953 abstract artwork Sacco, or Sack, by Alberto Burri, whose layers of worn sacking are perforated by a red circle that could be bloody stigmata.
Burri once had an exhibition in Assisi and his humble assemblages helped pave the way for Arte Povera, the 1960s Italian art movement that rejected plastic-fantastic modernity and instead brought natural, even living materials into the gallery. Right at the heart of this show is the Arte Povera sculptor Giuseppe Penone’s 2012 work Door Tree, a fat cedar trunk with a section cut from it to reveal what looks like a youthful sapling, still fresh and vital deep within the old exhausted bark.
This ecological artwork calling us to empathise with imperilled nature is truly in tune with Saint Francis. There were no factories or autostradas wrecking nature in 13th-century Umbria, but his sympathy for fellow creatures defied a Christian hierarchy that said animals were created for human beings’ benefit. In a manuscript illumination done only two decades after he died, the English artist-chronicler Matthew Paris portrays Francis bowed down to speak to an attentive gathering of birds. In a painting from 15th-century Siena by Sassetta, we see how he negotiated a truce between the people of Gubbio and a wolf that had terrorised them. He shakes the wolf’s paw gently.
You could tell the story of Saint Francis and art in a more conventional way. It is arguable that his direct, eloquent approach to life and feel for nature kicked off the Italian Renaissance. Giotto painted frescoes of his story that brought a new humanity to art. But instead of a blow-by-blow account of how this preacher changed art history, this show explores how he urged us to change our lives. Beggars, Andrea Büttner’s 2016 series of giant woodcuts, challenges you with stark images of fellow humans in need. In other contexts, her work has struck me as annoyingly pious but an exhibition of religious art suits her perfectly.
The church, of course, betrayed and contained Francis almost from the moment he died. He was turned into an icon and the Franciscan friars who were supposed to continue his work soon became as corrupt as other orders. In the Counter-Reformation of the 16th and 17th centuries, when the Catholic church was reinventing itself as a popular faith to fight the Protestants, it revived Saint Francis as a figure of melting mysticism. That produced the greatest painting here.
Caravaggio was in his 20s and living in the household of a cardinal in Rome when he painted Saint Francis of Assisi in Ecstasy. A good-looking angel cradles the swooning saint in his arms in what may be Caravaggio’s most explicitly gay painting – and his most tender. Saint Francis is truly unmanned as he sinks, falling into the angelic embrace. The divine youth looks at him with gentle love. The saint’s bearded face, freed from his friar’s hood, is surely Caravaggio’s.
Francis – or the artist – seems to have stigmata, the uncanny phenomenon in which a mystic apparently receives Christ’s wounds: the angel fingers a bloody gash in the saint’s side, echoing where Christ was speared on the cross. Francis/Caravaggio so identifies with Christ that he is experiencing the agony of the Passion. Yet he is at peace. This death is release, this intimacy an undoing. Caravaggio paints a love without limits, the longing for human contact of a man who was driven to fight, threaten and kill on Rome’s violent streets.
This masterpiece, borrowed from the Wadsworth Athenaeum in Connecticut, lifts a fascinating exhibition into realms of transcendence. A previous National Gallery boss, Neil MacGregor, put on a major show that argued for the power and glory of Christian art. Finaldi restates that here for a new age, in a more radical and socially charged way. Count me converted.
• Saint Francis of Assisi is at the National Gallery, London, from 6 May to 30 July.
