Portrait of the artist: The life and art of Jackson Pollock

He was a drunk, a depressive and a wife-beater. Many say he was also a genius. As one of his paintings sells for a record $140m, David Usborne looks at the private side of 'Jack the Dripper'

If he were alive today, Jackson Pollock, the American painter who electrified the art world with his eruptions of swirling lines and squiggles, would be puzzled by the news. How could it possibly be that one of his paintings - not a Picasso, a Gauguin or Van Gogh - has become the most valuable in history?

After all, not everyone has ever been quite convinced about Pollock and his genius, never mind that he was a drunk, a philanderer and a depressive. Isn't it possible that you or I could splatter some paint around on an empty canvas and command an entire wall of the Museum of Modern Art with the result?

Miraculously, we don't have to invest in tubes of paint to attempt such an experiment, or buy a house and barn in The Hamptons of Long Island in the wood-shingle style of the home occupied by Pollock and his artist wife, Lee Krasner, in the last years of his life. Rather, just click on the very cheeky website www.jacksonpollock.org and do your own drip painting with easy movements of your mouse.

So we can all be Pollocks now. But there is no arguing with the passion felt by some for the man whose demise came in a car crash in 1956 when he was only 44 years old (he was drunk at the time). The fascination with the man whom Time magazine dubbed "Jack the Dripper" at the time of his death only seems to get deeper.

Though it has yet to be confirmed by either party, a little-known Mexican financier named David Martinez has just shelled out $140m (£73.3m) for what is admittedly a very large Pollock painting named No. 5, 1948. The seller was David Geffen, the Hollywood mogul, and the price - at $4m per square foot - is assuredly the highest ever paid for a single work of art.

Pollock was not an artist who only became popular posthumously. Thanks in part to the patronage of the socialite collector and heiress Peggy Guggenheim, he was successful long before his death and even a bona fide celebrity of the art world. By the time he died, some critics were hailing him as one of the masters of 20th-century art. They even gave his style a name - abstract expressionism. The manner in which he created his works - by dripping and pouring paint onto the canvas - they called "action painting".

There has never been much mystery about Pollock's unusual mode of creation. Earlier in his career, his art was more representational, inspired in part by Picasso and the 20th-century muralists of Mexico. But in around 1947 - three years after he married Krasner and moved with her to Springs outside East Hampton - he embarked upon the drip series of works that made him a legend.

Nor have fans of Pollock ever had any illusions about the artist's state of mental instability.An abuser of alcohol all his adult life, he suffered a nervous breakdown in 1938 while still living and working in lower Manhattan and was briefly hospitalised for depression. Thereafter, however, there were signs that Pollock's personal and professional life might achieve some equilibrium. In 1943, Guggenheim gave him his first solo show at her Art of this Century gallery. In 1944, he married Krasner, who was already his long-time lover, and they bought the Springs house together. He was also undergoing intensive psychotherapy at the time - a process that many believe influenced the work of his most productive period in the late 1940s and early 1950s.

Visitors to the wooden barn at Springs did not find the usual implements of the painter. Pollock had no easel and no stretched canvases. His signature works were created instead by the painter standing above canvases, or sometimes squares of fibreboard, laid on the barn floor. His brushes did not touch the surface but were used rather to swipe and gesticulate in violent motion.The results are his masterworks of tangled lines and swirls of which the painting just acquired by Mr Martinez is a leading example.

"My painting does not come from the easel," he said. "I hardly ever stretch the canvas before painting. I prefer to tack the unstretched canvas to the hard wall or the floor. I need the resistance of a hard surface. On the floor I am more at ease. I feel nearer, more part of the painting, since this way I can walk around it, work from the four sides and literally be in the painting. I continue to get further away from the usual painter's tools such as easel, palette, brushes, etc. I prefer sticks, trowels, knives and dripping fluid paint or a heavy impasto with sand, broken glass or other foreign matter added."

The process was one of intense concentration and, art scholars surmise, a frantic expression of his emotions and the fruit of his long sessions in psychotherapy. He called his works explosions of unconscious imagery. "When I am in my painting, I'm not aware of what I'm doing," he said. "It is only after a sort of 'get acquainted' period that I see what I have been about. I have no fear of making changes, destroying the image, etc, because the painting has a life of its own. I try to let it come through. It is only when I lose contact with the painting that the result is a mess. Otherwise there is pure harmony, an easy give and take, and the painting comes out well."

One person who was able to watch Pollock at work was the photographer Hans Namuth. One day in 1950 he arrived at Springs after arranging with the painter to take pictures of him in the barn. On his arrival, he was put out to find Pollock standing over a canvas in the barn that apparently was already done.

"A dripping wet canvas covered the entire floor," he later recalled. "There was complete silence ... Pollock looked at the painting. Then, unexpectedly, he picked up can and paint brush and started to move around the canvas. It was as if he suddenly realized the painting was not finished. His movements, slow at first, gradually became faster and more dance-like as he flung black, white, and rust-coloured paint onto the canvas. He completely forgot that Lee and I were there; he did not seem to hear the click of the camera shutter ... My photography session lasted as long as he kept painting, perhaps half an hour. In all that time, Pollock did not stop. How could one keep up this level of activity? Finally, he said 'This is it'."

The first of these new drip paintings won public exposure at a solo exhibition at the Betty Parsons Gallery in Manhattan in 1948. The show was an instant sensation and a sell-out. Pollock moved to a larger studio in East Hampton. He was profiled in Life magazine in 1949 as possibly "the greatest living American artist" and in 1950 he produced a series of six paintings for which he remains most famous. At the same time, he appeared to be winning his battle with alcoholism, intermittently staying dry.

The stability did not last long, however. By the early 1950s, Pollock was drinking again, frequently violent towards his wife, and unable to repel repeated bouts of depression. He also failed to be faithful. When he crashed his car, an Oldsmobile convertible, on 11 August 1956, killing himself and another passenger, Edith Metzger, the survivor was his girlfriend of the time, Ruth Kligman.

During his life, Pollock turned out an estimated 350 paintings, some in the drip style and others, from earlier in his career, still abstract but bearing some degree of representation. Arguably, the current cult of Pollock worship was born the day one of his paintings sold for the highest amount of money ever paid for a single piece. That was back in 1973, when the National Gallery of Australia paid $2m for his 1952 painting Blue Poles. The artist was in the headlines again in 2004, when a collector paid $11.7m for one of his paintings.

If Pollock's popularity is ever to fade away, there are surely no signs of it yet. In 2000, a much wider public became aware of his work and of his turbulent life with the release of the film, simply named Pollock, directed by Ed Harris, who also played the title role.

In theory, all the remaining works of Pollock were sold by his own gallery upon his death. But even today our intense interest in him is periodically reignited with the discovery of new works that were previously unknown. Most famously, in 2003 a New Yorker named Alex Matter declared that he had fallen upon three dozen previously hidden Pollocks in a storage locker in Manhattan that contained the belongings of his late father, Herbert Matter, a photographer and designer who was a long-time friend of the painter and Lee Krasner. Herbert Matter died in 1984, two years before Krasner also passed away.

The 36 works - two dozen paintings and another 12 sketches - remain at the centre of a furious debate as to their provenance. The Straus Centre for Art Conservation at Harvard University is expected to declare within weeks its own judgement on their authenticity. Meanwhile, they are being shown publicly for the first time by Museum of Art in Syracuse, New York.

Then last month, an auctioneer cataloguing the belongings of a wealthy woman in Wisconsin found a picture that also bears the hallmarks of Pollock's drip-painting style. Moreover, the owner, Lynn Anderson, a renowned architect who is incapacitated and unable herself to explain the history of the painting, had written this note on its reverse: "Bought in New York in 1959 or 60" and the name "Jackson Pollock".

Even though the auctioneers made no attempt at authentication nor offered any guarantees as to whether it was real or fake, it was bought by Bill Kolb, an artist from Texas, for $53,000. "I've been looking at [Pollocks] for 40 years," he said. "My gut tells me this is real." Such is the power of Pollock's pull on our imagination even the possibility of owning one of his pieces has now become a five-figure prize. For his $140m, however, Mr Martinez has a Pollock about which there is surely no doubt at all.