In Vincent's footsteps

Van Gogh slept with countless prostitutes and even gave his ear to one. But the importance of sex in

I have this creepy feeling that I've been watching a cult being born. All I have really been doing is following in the footsteps of Vincent Van Gogh for a TV biography on Channel 4. But, at every step of the way, I found myself encountering so much bogus spirituality. People giving themselves to him, as it were. Worshipping him. Preserving his relics. Becoming Van Gogh's disciples. And in order to succeed with this weird sanctifying process, they have had to misunderstand Van Gogh completely. Almost to rebuild him from scratch.

This is not what the documentary is about: the three films closely follow his life. But the experience of making them was a revelation. What, for instance, are we to make of events in Van Gogh's home town of Zundert? The people there didn't like him much when he was alive, but today he is the subject of an annual flower festival, held in this small Dutch settlement close to the border with Belgium, and therefore full of Belgian madness. During the festival, millions of dahlias are used to create giant floats featuring towering horticultural Vincents, 40 feet tall, which are paraded along the main street to the accompaniment of brass bands, American-style prom queens, kids rattling buckets, and beauty pageants. Vincent with his ear cut off. Vincent suffering behind bars. Vincent committing suicide with the crows. It's bloody noisy, and bloody ridiculous. If you're in the audience, the giant floral likenesses of the world's most popular artist loom over you like deities. Here, remarkably, the Dutch behave like Hindus.

What is also interesting is the money that is being made out of Van Gogh, chiefly in the places where he was least valued when he was alive. Anyone who has been to Arles will know how determinedly it tries to brand itself as Van Gogh's town, yet in 1889 the ancestors of these Provencal locals officially petitioned their mayor to have him locked up. Now he is the town's chief money-spinner. It doesn't take much of a shift of angle to see all the Van Gogh knick-knacks being peddled in the streets, the T-shirts, the ashtrays, the fridge magnets, as the equivalent of those rubbishy relics that get flogged at religious pilgrimage sites the world over, from the Vatican to the Temple of Ten Thousand Buddhas. Money and ersatz spirituality are traditionally bedmates.

Nuenen, up the Dutch motorway from Zundert, where Van Gogh lived and worked in the early 1880s, is even more rapacious. The restaurants are invariably called things like Cafe Van Gogh. Plastic sunflowers pop up in every window. There is even an off-licence on the main street called Sans Oreille ("without an ear"). Nuenen is another town that ran Van Gogh out. After he was accused of making a girl pregnant, the local Catholic priest preached against him from the pulpit and banned any of his parishioners from posing for him.

Vincent Van Gogh has become a weird and absurd contemporary fiction. Given that no artist has ever been as famous, or as popular, as Van Gogh today, and because an unprecedented number of admirers have been involved in the creation of this myth, it seems likely that he is the most widely misunderstood painter there has ever been. The Van Gogh we have created is a far closer relative of the Maharishi Mahesh Yogi than he is of the real Vincent Willem Van Gogh, born in Zundert, Brabant, on 30 March 1853, a wiry redhead with a nasty temper, a voracious sex drive and an inglorious sense of victimhood.

Following in the real Vincent's footsteps tells us a great deal about this misrepresented figure. For instance, when you pace out exactly the journey he made to work when he lived in London in 1873-74, and had to walk from Brixton to Covent Garden every day, you get a real sense of his physical vigour. He used to do it in a sprightly 45 minutes each way. I waddled the same route as quickly as I could in a live TV recreation and it took me an hour.

His journey took him past the Oval, so the smack of willow on leather would have pressed itself on his Calvinist consciousness. He went past the Houses of Parliament, and the whores of Covent Garden. There is a theory that he lost his virginity to an English prostitute from Drury Lane. When you retrace his steps around the shop where he worked as an art dealer (it is now a branch of Wagamama), you realise it would have been impossible for him not to be regularly accosted of a lunchtime. Did he succumb? He was 20 years old, away from home, frustrated, a lover of sex (as became clear later in his life). I think he succumbed all right.

All this feeds into his work at some point, and also adds to our understanding of Van Gogh himself. He slept with a lot of prostitutes; later on, he lived with one. When he mutilated his ear in Arles he wrapped the bits he had cut off in newspaper, and gave them to a prostitute. It was probably from a prostitute that he caught the syphilis that no one likes to talk about. Van Gogh the brusque and thrusting sexual being is given prominence in my TV life because I think we have been wrong not to think of him that way.

Retracing Van Gogh's footsteps also brings you face to face with people's current view of the artist. Everywhere you go, you encounter stories about him. Thus, in Auvers-sur-Oise, the man who owns the inn where Van Gogh died, and who has turned it into a lucrative restaurant and visiting site, tells of how he crashed his car right outside. Feeling that this must be a sign, he bought the inn, gave up his old life and became a follower of Van Gogh. The room in which Van Gogh actually died has had everything taken out of it and confronts the paying public with nothing except a palpable sense of emptiness. There is something almost damascene about the innkeeper's dramatic conversion.

If ever an artist's reputation needed an injection of coarse sexuality, it is the sweetly mythologised sunflower-painting, creepily saintly Vincent Van Gogh. Not because it makes him more interesting, or modern, but because this paragon to whom flower festivals are devoted is good only for worshipping.

Vincent: the full story begins on Channel 4 on Sunday 16 May at 8pm

Waldemar Januszczak is art critic of the Sunday Times