Visual Arts/Aidan Dunne: There is still debate as to whether his host was laughing with him or at him when Henri Rousseau attended a riotous banquet in his honour at Picasso's studio in 1908.
This event, mythologised in Gertrude Stein's The Autobiography of Alice B Toklas, has been the subject of myriad interpretations.
Rousseau, gullible and pompous, was lauded as the great artist he took himself to be. Installed on a makeshift throne, he tearfully accepted the tributes of his peers who, it has to be said were, by all accounts, making fun of him.
Picasso, too, was making fun of him, but it is also true that Picasso admired his work. He had recently bought a Rousseau portrait which he regarded as brilliant and, within a decade, his own work showed signs of his having assimilated aspects of Rousseau's simplified, pedantic mode of representation.
As the Tate Modern's current, very popular exhibition Henri Rousseau: Jungles in Paris demonstrates, Rousseau was a great artist, just not the kind of great artist he thought he was. He aspired to excel in the grand tradition, to be welcomed into the academy by the pillars of the artistic establishment.
In the event the establishment scorned him, and it was an early advocate of outsider art, the dealer Wilhelm Uhde, who first appreciated what he was doing. Uhde was followed by avant garde artists such as Picasso and Robert Delauney, and, subsequently, the Expressionists, the Surrealists and even Pop artists. Many of his paintings have attained iconic status and are fondly regarded, including Surprised!, a tiger caught in a storm in one of his fantasy tropical forests, The Sleeping Gypsy in a multi-coloured robe, overseen by a lion (which didn't make it to this show), the haunting Snake Charmer, and The Dream, in which a contemporary Venus dreams that she is in a lush forest.
Rousseau was born in northwest France in 1844. After rashly becoming involved in some small-scale pilfering while working in a solicitor's office, he volunteered for army service and became a bandsman. It was later claimed (by admirers rather than the artist), he took part in the Mexican campaign, gathering material for the more exotic of his subsequent paintings. In fact it seems unlikely that he ever went to Mexico, and one of the achievements of the Tate exhibition is that it locates the inspiration for his tropical fantasies much closer to home. On his father's death he was discharged, worked to support his mother, and married Clemence Boitard. Six of their seven children died in infancy and Clemence died from tuberculosis in her 30s. (He subsequently remarried, and outlived his second wife.)
In the meantime, after another brief bout of army service during the France-Prussian War, a relation of Clemence's secured Rousseau a job as a municipal customs officer in Paris - hence his nickname, Le Douanier. The work was pedestrian, but he certainly had a rich inner life. Not only did he take up painting seriously when he was about 40, he also composed poetry and music, wrote plays and played the violin. His self-confidence was extraordinary, surviving in the face of public scorn and the disdain of the professionals. Despite an early success with Surprised! in 1891, he didn't return to the jungle as a subject for another 10 years or so. He retired his customs post around 1894 to pursue painting full-time, but money was short and he supplemented his pension by teaching painting, music and elocution.
He painted suburban scenes, portraits, flower pieces and allegorical subjects. Almost everything he approached he rendered with a disarming frankness, so that his suburban studies are like low-key documentary photographs, relatively uneventful as paintings within the conventions of the time, and yet all the more informative for that.
The portraits are stark and confrontational, stilted-looking and painstakingly made. The proportions are usually wrong, and if the subjects are children they can look rather fearsome. Still, as Picasso noted, they are compelling in their honesty. His stylised allegories can fall flat, lacking the magic of his best jungle fantasies, but some of them are remarkable, including the stark War, which usually hangs in the Louvre and surely exercised a profound influence on several generations of painters, including Picasso.
The suggestion that Rousseau drew on apocryphal Mexican experiences was probably made to justify, in a sense, his use of exotic jungle imagery. As the show's title indicates, Paris has its own jungles, in the form of the Jardin des Plantes, which the painter visited regularly and where, he said, it was as if he entered into a dream. Just as Picasso's work was an amalgam of myriad influences and appropriations, so Rousseau's jungle paintings were derived from his studies of the lush foliage of the Jardin des Plantes and other sources.
His animals are recognisably related to, for example, those depicted in the album Betes Sauvages and other printed publications. None of which diminishes his work. Indeed it was the disconcerting, improbable elements of what he did that appealed to later artistic sensibilities. His dreamer in The Dream, transported into the luxuriance of a forest, may have dismayed its literal-minded audience in 1910 but made perfect sense to the Surrealists. At times like this the very awkwardness of Rousseau's manner, his undoubted technical limitations, help rather than hinder in the shaping of a startling poetic vision.
His reputation rose swiftly following his death, from blood poisoning, in 1910. This exhibition consolidates his already secure reputation, illuminates his way of working and his source material, and probably indicates the limits of his abilities. In other words, the best-known works still look best. There are no astounding revelations. But it still provides a vivid and exciting experience.
• Henri Rousseau: Jungles in Paris is at the Tate Modern, London until Feb 5 (admission £10)
