Preview Miro, Retrospective: Talk quietly, and carry a big brush

He painted with Picasso, boxed with Hemingway and defied Franco… Nina Caplan judges the silent genius of Catalonia by the company he kept

For a man who spent the second half of a long life painting quietly in a forgotten corner of Franco's Spain, the Catalan artist Joan Miró had a surprising number of well-known friends. It was not charm that won them. One journalist likened him to the albatross in Baudelaire's poem: a king in the air but a helpless figure on the ground. Louisa James Calder, wife of the American artist Alexander Calder, put it more succinctly: "Miró never talks." One imagines it can't have been hard for the laconic young artist to follow his Spanish dealer's odd advice, on his first visit to Paris in 1920, to tell no one anything about his work.

"I keep exclusively to the world of painting," he once said, yet Miró befriended many of the most important creative people of his remarkable age. Picasso, who had attended the same art school in Barcelona 12 years before him, was an early mentor. (Picasso, Miró said wryly, was recognised as a prodigy by their teachers, while he himself was viewed as "a phenomenon of clumsiness"). Already hugely famous by 1920, the older Spaniard nonetheless "was very welcoming and scolded me because I hadn't been [to his studio] more often. He shows a lot of interest in my things." Their relationship would last until Picasso's death in 1973. "Picasso played a vital role, encouraging and reassuring him, which was very necessary because Miró was overwhelmed by Paris – he'd never even been as far as Madrid before," says Matthew Gale, co-curator of the Tate Modern's upcoming retrospective. "And then, in the later 1920s, Miró took that same role for Dalí. It was like a relay of Catalan artists!" Miró and Dalí later fell out over the latter's fascination with Hitler but other Catalans proved more durable. The sculptor Josep Llorens Artigas was a lifelong collaborator; the architect Josep Lluís Sert built Miró's Mallorca studio and, at his instigation, the marvellous Fondation Maeght near Nice for Miró's dealer, Aimé Maeght.

Alberto Giacometti and Alexander Calder were vocal admirers and even, to an extent, imitators. "Miró," said Giacometti, that creator of light and aerial human figures, "was utter freedom: something lighter, more aerial, more disengaged than I had ever seen." In 1943 Calder started a series of mobiles called Constellations, in direct homage to Miró's paintings of the same name, begun in Normandy after he fled the Nazi occupation of Paris, and finished in Palma, Mallorca, in 1941. (Miró had managed to board the last train south. His wife carried their small daughter; he carried his canvases.) Miró was to move between Palma, his birth city of Barcelona, the family estate of Montroig in the Catalan countryside and – once the war ended – Paris, from then until his death, in 1983, at the age of 90.

Joan Miró, son of a jeweller on one side and grandson of a cabinet-maker on the other, was never supposed to work with his hands: his father ordained he should be a businessman, but two years of that made him literally sick. He came down with typhoid, or possibly worse: the painter and professional hagiographer Roland Penrose, a friend for 50 years, claims the work precipitated a nervous breakdown. Penrose also suggests that Miró's lifelong taciturnity was a result of his father's bullying. "We saw a long interview with him," Louisa James Calder told a journalist, "but I think the reporter must have invented it. We've spent days and once even a week with Miró, and he's never said anything to us but 'Comment ça va? Ca va?' Yet Miró wrote a poem for his friend ("My old Sandy, this burly man with the soul of a nightingale ...") which, like the art with which he always strove to administer a "poetic shock" to the viewer, is both pretty and powerful.

Miró's work was always rooted in Catalonia, but he flowered in Paris, learning from Picasso and Cubism, painting in a studio next to André Masson's (he painted in silence, alone, during the day, while Masson worked nights amid music and card games) and befriending the Surrealists, particularly poets such as Paul Eluard. In fact, it was Eluard who played peacemaker when Miró's involvement with the Ballets Russes caused outrage among more doctrinaire Surrealists – he and Max Ernst, along with Picasso and Man Ray, designed sets for Diaghilev, to the fury of Surrealism's inventor André Breton and others, who considered ballet frivolous.

In 1927, Miró moved Paris studios, keeping his former friends and gaining new ones, including René Magritte and the Austrian sculptor Jean Arp. Miró's work ethic, however, occasionally offended the artists around him: a drunk Max Ernst once tried to hang him for carrying on painting when everybody else downed tools due to a power cut. Despite this, and the odd sale – his boxing partner, Ernest Hemingway, who would later visit Montroig, plunged into debt to buy Miró's early masterpiece The Farm in 1922 (he said "it has in it all that you feel about Spain when you are there and all that you feel when you are away and cannot go there") – the artist was not yet comfortably off, and he and Arp often shared spartan meals of radishes and butter. "We were seeking ... to cure the madness of the age," Arp, who had been a member of the Dada movement, would remember of that time, "a new order of things that would restore the balance between heaven and hell".

History was against them. Miró's exuberant and playful celebrations of the Catalan landscape (The Farm, The Hunter), of his painterly forebears (Dutch Interior I, Portrait of Mrs Mills in 1750), of womanhood (Maternity) and of play itself (Harlequin's Carnival) darkened as peace faded. First his homeland disintegrated into civil war; then the rest of the world followed suit. By 1937, when the Spanish Republican government commissioned a giant mural to hang alongside Picasso's Guernica in the Spanish Pavilion (designed by Sert) at Paris's World Exhibition, Miró created The Reaper, a supersize exclamation of despair and defiance, now lost.

After the war, Miró chose to remain in Franco's Spain, and despite his blatant support for the Republic that Franco had vanquished, he was left alone. His international reputation grew, even as his homeland paid him scant attention: Matisse's son, Pierre, exhibited him in New York; Maeght showed his work at his new-built foundation in 1948.

There were many other collaborations: a series of public murals with Artigas, a beautiful book with Eluard. His 22-metre high 1962 statue, Woman and Bird, now in a Barcelona park, is part homage to the maddened writings of the playwright Antonin Artaud, an early Surrealist influence whom Miró loyally visited in the asylum in the 1940s.

In 1976, the octogenarian artist extended his friendship to a group of young Catalan actors, designing a host of crazy creatures for their play Mori el Merma, celebrating Franco's death. This much-anticipated demise at last allowed the artist's renown to spread from the world outside to Miró's homeland, and the artist who once claimed he wanted to assassinate painting – and whom Ernst very nearly did assassinate – died world-famous, which makes it odd that this is his first big British retrospective in 50 years.

His Mallorca studio is now a foundation dedicated to his life and work, and there is another in Barcelona. Both are designed, of course, by Sert: now posthumous and slightly quieter than before, Miró still stands by his friends.

Miró at Tate Modern opens 14 Apr; tate.org.uk/modern