Sir Anthony Caro: Sculptor acclaimed as the greatest British artist of his generation

In 1963, Anthony Caro, who has died following a heart attack, did a thing that seems unremarkable now but which rocked British art to the core and launched him as an enfant terrible. Given a retrospective at the Whitechapel Gallery in London, the artist, not quite 40, filled the rooms with works he had made in the previous three years. Most of them he sat on the gallery floor.

It was the second of these things that caused consternation. Since Classical antiquity, sculpture had been shown on plinths. It was bad enough that Caro's work was abstract, and that much of it – most memorably, the yolk-yellow Midday and bus-red Early One Morning – was made of steel girders clamped together with industrial bolts and then painted. Showing his sculpture on the Whitechapel's floor challenged common decency, inverted the natural order of things. Critics and visitors united in outrage and Caro's career never looked back.

The shock was all the greater because, not long before, Caro had been anointed as heir apparent to Henry Moore by no less a critic than David Sylvester. In 1951, when still a student at the Royal Academy Schools – at his father's insistence, he had first done a degree in engineering at Cambridge, and then served as a wartime officer in the Fleet Air Arm – Caro had tired of the conservatism of teachers such as Siegfried Charoux and Maurice Lambert – "Old Academicians who did sculptures of generals," as he later described them.

With the benign self-assurance of the public schoolboy he was (his father had also sent him to Charterhouse), Caro turned up on Moore's doorstep in Much Hadham in Hertfordshire and applied to be his studio assistant. The great man, taken aback, told him to carry on at the RA and to come back six months later if he still wanted the job. Caro did, and was taken in.

For two years he and his wife, the painter Sheila Girling, lived in a cottage in the village, Caro cycling up to Moore's studio each morning and using his engineering skills to sort out problems with the older man's home-made bronze foundry. In 1953 the couple left Hertfordshire with their first son, Timothy, and settled in Hampstead. There, Caro made a series of figurative works with names such as Man Holding his Foot, either loosely Moore-ish in feel or with nods to Moore's hero, Picasso. In the insular, reactionary world of postwar British art, these references made the young sculptor seem breathtakingly modern. It was at this point that he came to the attention of David Sylvester, who in 1955 pronounced him to be the coming man. "Of all the new sculptors," he wrote, "the most impressive seems to me to be Anthony Caro."

That Sylvester was, untypically, to eat his words eight years later was the result of a meeting with another critic, Clement Greenberg. In 1959, Caro was introduced to Greenberg in London; later that year he travelled to New York on an English Speaking Union grant. If Sylvester was the champion of the so-called School of London – at heart, a figurative late flowering of Surrealism – Greenberg was the high priest of Abstraction. While in New York, Caro was introduced to David Smith, the American sculptor famed for his welded steel abstracts. His conversion to the Greenbergian camp was more or less instantaneous.

Back home in London Caro set to work straightaway on a welded steel sculpture called Twenty-Four Hours, once owned by Clement Greenberg and now in the Tate collection. Its materials and simple forms – a circle, a square and a rhombus – were like nothing ever seen in British sculpture. Even more shockingly, Twenty-Four Hours was painted brown and black because, as Caro explained, he didn't want the work to "get any credit for looking like sculpture ought to look, that is, by looking like bronze." (Ever the engineer, he pointed out that paint also keeps steel from rusting.) Critics, Sylvester included, were appalled.

Thirty years earlier, Ben Nicholson had faced the opposite problem when his carved White Reliefs were accused of being sculptural rather than painterly. Nicholson had been influenced by working alongside Barbara Hepworth; in the same way, the painterliness of Caro's work, and particularly its fascination with Matisse, may have come from his wife, Sheila Girling. His sculptures of the 1960s were essentially made up of a series of two dimensional surfaces arranged to interact in space. As his mentor, Clement Greenberg, observed, "there are no volumes in Caro, only planes, linear forms and shapes."

This two-dimensional quality evolved into a more volumetric style as the 1960s progressed. In 1967 Caro bought a stock of raw materials from the estate of David Smith, killed in a car crash two years before; 1968 saw the beginning of a series of Smith-like table sculptures. The following year he moved his studio to a piano factory in Camden Town where he hired the assistant Patrick Cunningham, who was to stay with him there for the rest of his life.

With Cunningham, Caro began to integrate bits of agricultural machinery, notably ploughshares, into his work. A stint at a steel mill in Ontario in the mid-1970s allowed him to branch out into larger-scale sculpture, leading to commissions for public spaces. A show at MoMA in 1975 was followed, the next year, by the freedom of the city of New York. His arrival in the British Establishment was confirmed in 1987 by a knighthood.

As with many artists, public acceptance did Caro's critical reputation few favours. By the early 1990s the abstraction with which he had caused such a furore 30 years earlier had come to seem passé. Sculpture was now dominated by the postmodern ironisings of Jeff Koons, the post-post-Surrealist fantasisings of Damien Hirst. Caro, rolling with the punches, took the changes in his stride.

"You wouldn't really have talked to Degas about Cubism in 1917 when he was 76, and you wouldn't have talked to Monet about Surrealism when he was in his eighties," he reasoned, happily owning up to being old hat. "That would have been silly." If anything he claimed to feel liberated by his own fall from critical grace. "There was a period in the '70s where I knew much more where I was, what I was going to do", he said. "Now I don't know where I am and I love it."

Critics, predictably, did not always agree, Caro's work from this time on seeming to lack the conviction of his youthful sculptures. Where the public had been horrified by his descent into abstraction in 1963, it was equally appalled in 1993 by what looked like the return to figuration of works such as The Trojan War. Disapproval turned to outrage with the appearance of The Barbarians in 2002, the piece consisting of a cavalry of wooden gymnasium vaulting horses bearing sword-wielding terracotta soldiers. Caro cautiously allowed that both of these late pieces might be open to political reading, having been made in response to the first Gulf War and the turmoil in Yugoslavia, respectively. His insistence that they remained abstract none the less was harder to follow.

For all that, he was never short of admirers, or of energy. At the age of 88 he designed both a massive public artwork for Midtown Manhattan and a gold kilo coin for the 2012 London Olympic Games. He was also given a 50-year retrospective in the grounds of Chatsworth House, while another retrospective, at the Museo Correr in Venice, which opened in June as part of the Bienniale, closes in a few days. "I've always kept going by thinking about tomorrow, not yesterday," he said in an interview last year. "I'm not going to stop now."

Charles Darwent

Anthony Alfred Caro, sculptor: born New Malden, Surrey 8 March 1924; CBE 1969, Kt 1987, OM 2000; married 1949 Sheila Girling (two sons); died London 23 October 2013.