Anish Kapoor: Maverick let loose in art's hall of fame

The only time I'd met Anish Kapoor, he was leaning over a balustrade at the Musée des Beaux-Arts in Nantes, looking unassuming and cheery. Below, in the sculpture court, local art students laid the rails for Svayambh, a work that would drag a vast block of wax on a freight car through the court's too-small main arch. The museum was faced in tufa, an unlikeably dead pale stone. As Kapoor's juggernaut forced its slow way through the arch, it left a growing crust the colour of old blood on the pristine soffit and sides.

The effect was of rape, but also of murder: for all the whiteness of its art museum, Nantes had a bad war record, deporting its Jews to death camps. Down in the court, the students slithered about in wax, red from hair to feet like souls in torment. Kapoor, the son of an Indian Hindu father and an Iraqi-Jewish mother, pondered it impassively. Then he burst out laughing and squealed, "It looks like Hell!"

Now, two years later, Svayambh is coming to London in a huge retrospective, a behemoth that will see the entire Royal Academy – galleries, courtyards and common parts – filled with 30 years' worth of Kapoor's work. Burlington House is hardly the kind of place you'd expect to find an anarchist, a man who says, "It's a moot point whether one has to have something to say, to express. I mean, who gives a shit?" But then Kapoor is the rare example of an artist who has it all: the respect of his peers and the love of his public.

The figure that walks into the Academicians' room still looks unassuming and cheery. But, born in Bombay in 1954, Kapoor recalls growing up among "a post-Independence anxiety about Indian-ness". "My colleagues were obsessed, for ever and ever, with making something called 'Indian art'," he says. Then, in 1973, he arrived in London. "My family put pressure on me – gentle, but still pressure – to do electronic engineering or some such crap, which I did for six months. Back then, probably a handful of English artists were making a living – maybe Henry Moore, Francis Bacon. But I'd known from 17 that I was going to be an artist and ... oof, my poor father. So I went to [Hornsey] art school.

"When I started showing in London, I was always referred to as a female artist. I didn't mind that – I loved that" – he squeals – "but then the writing on my work began to be about how exotic it was, which irritated the hell out of me. I didn't want to play that game. No one would have talked about [US sculptor, Robert] Gober in terms of gay America and its exotic languages, and yet those were every bit as exotic as India. Maybe more so."

Today, where once a city would have bought itself an art museum, it may well now go for an Anish Kapoor instead. His name has become synonymous with vastness of scale at every level: Chicago's Cloud Gate (2004-6) is not merely a 10-metre by 20-metre ellipse of polished steel, it also cost $23m to make. The sculpture was, and remains, the most expensive public art commission in the world. He is currently making the world's largest commission, a £15m five-part suite known as the Tees Valley Giants, destined for five towns in the North-east of England. One, called Temenos and recently unveiled in maquette, will be 50 metres high by 110 metres long. By comparison, Marsyas, a trumpet of red membrane installed in Tate Modern's Turbine Hall in 2002-3, was a miniature.

So popular was Cloud Gate with Chicagoans that they awarded the sculpture its own public holiday, Cloud Gate Day. With his talent for the public and large-scale, the 55-year-old artist has even occasionally turned architect. In 2004, the city of Naples commissioned a sculpture-cum-subway which will one day ferry passengers to platforms under Monte Sant' Angelo station. Along the way, Kapoor has also attracted every accolade the English art establishment could throw at him – the British Pavilion at the Venice Biennale (1990), the Turner Prize (1991), his election to the Royal Academy (1999), a CBE (2003).

Nonetheless, he is a touch fretful at how Svayambh will play in London. "Seeing the work in Nantes gave it a kind of historical recall," Kapoor says, drumming his fingers. "In Munich, that recall was very, very strong – I showed it at the Haus der Kunst, Hitler's first, his only museum, a very great building in spite of its history – and there, of course, it had a whole other set of associations. Here, it's going to run through the enfilade of five rooms at the back of the main galleries. That's lots of doors. Lots."

One thing that won't have changed is that there will be more to Svayambh than meets the eye, and literally so. Physics dictates that the passage of any juggernaut through a given aperture will scrape off its excess wax in one go, and yet Svayambh's London scab will continue to grow over two-and-a-half months. Kapoor looks momentarily taken aback when I point this out, then smiles blithely: "In a way, it's a fiction, like pouring something into a mould or carving it – sculpture's always like that. It's very important to me that you can't tell how my work is made. Time and again, it goes back to other authorities." And the artist himself? "He's run away!" He squeals again. It is a very engaging squeal.

As explanations go, it is both candid and less so. The erasure of the artist's hand has been a staple of Minimalist art for half a century. Kapoor, though, is not a Minimalist in any useful sense of the word, although he has clearly taken this one tenet of Minimalism to heart. Svayambh means "self-forming" in Sanskrit, apparently relieving the author of the responsibility of having made it. And yet that relief is so typical of Kapoor that it is the very thing that links his otherwise impossibly different works.

Take Cloud Gate and Shooting into the Corner. The first is elegant, monolithic, silent and static; the second is a cannon that will fire 10kg drums of red wax, every 20 minutes and at 50km an hour, from the RA's Weston Room on to the wall of the adjoining gallery. Quite apart from the heroically sexual nature of this work – essays about Kapoor are peppered with the words "ejaculation" and "vagina" – Shooting into the Corner raises a question. Where, exactly, does its art take place – at the point of firing or on impact, in the projectile's trajectory, its percussion, its collision with the wall or all of the above? In this slipperiness, Kapoor's cannon is like the mirrored surface of Cloud Gate – an optic as much as a sculpture, a place on which we can never get a purchase: above all, where we can never get a purchase on Anish Kapoor.

"Where does my art happen?" he says. "It's a good question. I like that. My art is elusive, intentionally so. There's no avoiding one's own psycho-biography, it's unavoidable." (Like V S Naipaul, Kapoor is given to impersonal pronouns.) "The question is, where does one put the emphasis? What interests one is what an object can do rather than what it can say."

Still, there's a flaw. If self-denial is meant to hide Kapoor from his public, what it actually does is reveal his inner Kapoor-ness. The artist himself seems happy with this paradox. He describes the 16 years he spent in three-times-a-week analysis – a process that began in his twenties and ended just before his marriage to the art historian Suzanne Spicale in 1995 – as "the best but hardest work I've ever done". The couple have two children. "There's a feeling with lots of artists that art is an affirmation of self," Kapoor says. "You know, I make, therefore I am. But with me, a sense came three-quarters of the way through my therapy that the work was the work and I was me. And the work got 10 times better. It chilled out."

He pauses. "I had a conversation with the sculptor Richard Serra once – he was, ah, similarly burdened – and he said the same thing. There's an openness now to the half-resolved, the fractured. It doesn't mean the works are not resolved – I hope they are, I know they are. But they're open to anxiety, perhaps."

Of course, they can afford to be: commissions are hardly likely to dry up for the world's most successful sculptor. Anish Kapoor, RA CBE, looks across the table and beams. "In the Seventies I thought I was going to have to teach for the rest of my life," he says. "Things turned out to be easier than that, which was great. I've been amazingly lucky, really. Amazingly, amazingly lucky."

Anish Kapoor is at the Royal Academy, London W1, from 26 Sep-11 Dec (020-7300 8000); royalacademy.org.uk/exhibitions/anish-kapoor

The sculptor's story

1954 Born in Mumbai, India, to Hindu father and Iraqi-Jewish mother. His grandfather was a cantor at Poona synagogue. Educated at Doon School, the Indian equivalent of Eton.

1973 Moves to London.

1973-77 Trains at Hornsey College of Art

1977-78 Studies at Chelsea School of Art and Design.

1980 First solo exhibition.

1990 Represents Britain at the Venice Biennale; wins Premio Duemila prize.

1991 Wins the Turner prize.

1994 Marries Suzanne, a German-born medieval art historian met in Cologne.

1998 First major UK exhibition at the Hayward Gallery, London.

2002 Marsyas sculpture unveiled in Tate Modern's cavernous Turbine Hall. Considered the world's biggest indoor sculpture, it draws record crowds.

2003 Created CBE.

2004 Wins the competition to create a memorial to the 67 British victims of the terror attack on the World Trade Center in September 2001.

2009 Becomes the first British contemporary artist to be given all the main galleries at the Royal Academy for a major solo exhibition.