William F. Buckley Jnr: Hero of modern American conservatism who founded the influential 'National Review' magazine

Modern American conservatism has had three great heroes. One was Barry Goldwater, who set the stage for the movement's dominance of the last half century of US politics, and whom William F. Buckley fervently supported. The second was Ronald Reagan, 40th President and Buckley's friend and great admirer. The third was Buckley himself.

Editor, novelist, wit, polemicist, bon viveur, one-time CIA agent, failed New York mayoral candidate, scourge of liberals and, not least, an accomplished harpsichordist, William Frank Buckley was an American original. His most lasting legacy however was the National Review, the magazine he founded in the mid-1950s when the very term "conservative intellectual" was considered an oxymoron, and turned into the most influential political publication of its era.

Ordinary Americans probably knew him best as the presenter of Firing Line, the upmarket television talk show that ran without a break from 1966 to 1999, where Buckley's languid manner and silky, faintly foppish accent – half Wasp drawl, half received pronunciation dating back to his school-days in Britain – turned him into a minor national institution. His greatest weapon was the English language, whether written or spoken: in his hands nimble, fluid, precise and often deadly, enriched by a vocabulary that could have erudite men reaching for a dictionary.

Bill Buckley, or "WFB", as many referred to him, was born in New York, the sixth of 10 children of a Catholic lawyer and oilman. The exactitude of his English may well reflect the fact that it was his second language, after the Spanish acquired from Mexican household staff during his early childhood. He only truly mastered English in London, where he attended day school in the late 1930s.

The family returned to the US where Buckley completed high school and entered the military just before the end of the Second World War. Not until 1946 did he enter Yale, where he was a pillar of the conservative club and edited the Yale Daily News. Also, like many graduates of that university, he was recruited into the CIA. In the event he only spent a year with the Agency, as an undercover agent in Mexico City in 1951. Years later, he met the former Mexican President, who asked Buckley what he had done during his stay in the country. "I tried to undermine your regime, Mr President," came the reply.

But ideas, not espionage, were Buckley's stock in trade. By 1951, he had published his first book, God and Man at Yale, an early but remarkably assured critique of the university that could be read as his first conservative manifesto. In 1954 came McCarthy and His Enemies, a defence of the Red-baiting Senator Joseph McCarthy.

But Buckley's battle against the liberal culture that had dominated the US for a generation demanded a permanent weapon. Thus was born the National Review, in 1955. The initial reaction to the magazine was scorn on the left and a quiet excitement on the right, as the publisher set out his own views, with trademark trenchancy, in an early editorial. "Radical conservatives in this country have an interesting time of it, for when they are not being suppressed or mutilated by the liberals, they are being ignored or humiliated by . . . the well-fed right, whose ignorance and amorality have never been exaggerated, for the same reason that one cannot exaggerate infinity."

For "radical conservatives" might have been substituted the name Barry Goldwater. Strong support from the National Review helped the iconoclastic Arizona senator win the 1964 Republican Presidential nomination. In the election itself he would be obliterated by Lyndon Johnson, but in landslide defeat lay the seeds of conservatism's imminent triumph. Four years later Richard Nixon won the White House, and when Ronald Reagan came to power, he made Buckley's magazine compulsory reading for every staffer.

The National Review was also a hothouse nursery for journalistic and literary talent, its alumni including George Will, Garry Wills and Joan Didion. By dint of deft management and his own massive reputation, Buckley kept competing egos under control. As circulation rose eight-fold in two decades to 125,000, it became the conservatives' bible, and Buckley the movement's most glamorous figure.

The National Review was also highly entertaining. In one innovation, Buckley put readers' letters at the centre of the magazine, in a section called "Notes and Asides", where the editor was wont to answer some correspondence himself. Those who dared complain were often walking into a verbal chainsaw.

Arthur Schlesinger Jnr, the historian and liberal stalwart of JFK's Camelot, was a frequent adversary. "Dear Arthur," Buckley wrote in response to a protest at some perceived slight. "I should have thought you would be used to being wrong." Publicly, Buckley described Schlesinger as "the most overbearing liberal ideologue in the United States". On another occasion Schlesinger entered and won a National Review competition. As a prize, Buckley sent him a live donkey (the symbol of the Democratic party). In a diary entry during that period the historian called his tormentor "odious . . . the last thing in the world Buckley wants is to have facts violate his prejudices".

Later, the two made their peace. Maybe, two ageing men were realising the folly of their feud; perhaps Buckley's views were moderating; he came to oppose the criminalisation of drugs (there was always an attractive dose of libertarianism in his views), and in 2004 even conceded the Iraq war had been a mistake. Another reason, surely, was his personal charm, humour and grace. Even at his most excoriating, Buckley was hard to dislike.

Those traits were on vivid display in his stunt run for Mayor of New York in 1965, against the incumbent, his Yale classmate and liberal Republican John Lindsay. Buckley finished third, with 13 per cent of the vote. What would he have done if he had actually won, he was asked. "Demand a recount," he answered. And if elected, what would be the first thing he'd have done? "Hang a net outside the window of the editor of the [very liberal] New York Times."

In 1990 he finally gave up the editorship of the National Review, but his columns (typically written in 20 minutes) continued. So did the prodigious output of books, roughly one a year. Over his life he wrote more than 50, the bulk of them non-fiction, but also 11 spy novels featuring Blackford Oakes, a deep-cover CIA agent, whose adventures included a brief fling with the Queen of England. In 2004 he published Miles Gone By, an entertaining pot-pourri of Buckleyana. His last book was Cancel Your Own Goddam Subscription, a wicked 2007 anthology of the most torrid exchanges from the National Review's letters pages.

Much of this writing took place in Switzerland, where he wintered for six weeks every year near Gstaad, producing 1,500 words a day. There he lunched daily at a local inn, before skiing in the afternoon. Every evening in his study, he would host a cocktail-and-cigar hour for his house guests – a wide circle given Buckley's huge gift for friendship, not only with conservatives, but liberals like Norman Mailer and the economist John Kenneth Galbraith.

In that same spirit, political allies and opponents alike would appear on Firing Line, where for more than three decades Buckley presided with supercilious drawl and devastatingly raised eyebrow. Among his guests over the years were Mailer, Muhammad Ali, Jack Kerouac, Edward Teller, Germaine Greer, Noam Chomsky, not to mention presidents, senators and journalists – the latter including Malcolm Muggeridge, with whom Buckley had some of his most memorable debates.

Sometimes, of course, things did get out of hand. In the admittedly hyper-charged setting of the 1968 Democratic convention, tempers boiled over in a debate between Buckley and the author Gore Vidal. At one point Vidal called Buckley a "pro-crypto Nazi," to which Buckley replied: "Now listen, you queer, stop calling me a crypto-Nazi or I will sock you in your goddamn face, and you will stay plastered." More accusations and lawsuits followed, the lawsuits subsequently dropped, but Buckley emerged morally and financially ahead on points.

But that venom was uncharacteristic. His sense of humour usually stopped Buckley from taking himself over-seriously – as illustrated by the headline of a piece in the New York Times: "I am lapidary but not eristic when I use big words." He loved the cut and thrust of politics and ideas, but his Catholic faith and his family were at least as important. And life had so many other diversions; sailing, skiing, the harpsichord, the English language, to name but four. An old friend put it best. "His conservatism was not dour, but celebratory."

Rupert Cornwell

William Frank Buckley Jnr, commentator, broadcaster, publisher and writer: born New York 24 November 1925; married 1950 Patricia Alden Taylor (died 2007; one son); died Stamford, Connecticut 27 February 2008.