Henri Rousseau was born in Laval, France, in 1844 into the family of a plumber; he was forced to work there as a small boy.He attended Laval High School as a day student and then as a boarder, after his father became a debtor and his parents had to leave the town upon the seizure of their house. Though mediocre in some of his high school subjects, Rousseau won prizes for drawing and music. After high school, he worked for a lawyer and studied law, but "attempted a small perjury and sought refuge in the army." He served four years, starting in 1863. With his father's death, Rousseau moved to Paris in 1868 to support his widowed mother as a government employee. In 1868, he married Clemence Boitard, his landlord's 15-year-old daughter, with whom he had six children (only one survived). In 1871, he was appointed as a collector of the octroi of Paris, collecting taxes on goods entering Paris. His wife died in 1888 and he married Josephine Noury in 1898. He started painting seriously in his early forties; by age 49, he retired from his job to work on his art full-time.
Rousseau claimed he had "no teacher other than nature", although he admitted he had received "some advice" from two established Academic painters, Felix Auguste Clement and Jean-Leon Gerome. Essentially, he was self-taught and is considered to be a naive or primitive painter.
His best-known paintings depict jungle scenes, even though he never left France or saw a jungle. Stories spread by admirers that his army service included the French expeditionary force to Mexico are unfounded. His inspiration came from illustrations in children's books and the botanical gardens in Paris, as well as tableaux of taxidermy wild animals. He had also met soldiers during his term of service who had survived the French expedition to Mexico, and he listened to their stories of the subtropical country they had encountered. To the critic Arsene Alexandre, he described his frequent visits to the Jardin des Plantes: "When I go into the glass houses and I see the strange plants of exotic lands, it seems to me that I enter into a dream."
Along with his exotic scenes there was a concurrent output of smaller topographical images of the city and its suburbs.
He claimed to have invented a new genre of portrait landscape, which he achieved by starting a painting with a specific view, such as a favourite part of the city, and then depicting a person in the foreground.
Rousseau's flat, seemingly childish style was disparaged by many critics; people often were shocked by his work or ridiculed it. His ingenuousness was extreme, and he always aspired, in vain, to conventional acceptance. Many observers commented that he painted like a child, but the work shows sophistication with his particular technique.
From 1886, he exhibited regularly in the Salon des Independants, and, although his work was not placed prominently, it drew an increasing following over the years. Tiger in a Tropical Storm (Surprised!) was exhibited in 1891, and Rousseau received his first serious review, when the young artist Felix Vallotton wrote: "His tiger surprising its prey ought not to be missed; it's the alpha and omega of painting." Yet it was more than a decade before Rousseau returned to depicting his vision of jungles.
In 1893, Rousseau moved to a studio in Montparnasse where he lived and worked until his death in 1910. In 1897, he produced one of his most famous paintings, La Bohemienne endormie (The Sleeping Gypsy).
In 1905, Rousseau's large jungle scene The Hungry Lion Throws Itself on the Antelope was exhibited at the Salon des Independants near works by younger leading avant-garde artists such as Henri Matisse, in what is now seen as the first showing of The Fauves. Rousseau's painting may even have influenced the naming of the Fauves.
In 1907, he was commissioned by artist Robert Delaunay's mother, Berthe, Comtesse de Delaunay, to paint The Snake Charmer.
When Pablo Picasso happened upon a painting by Rousseau being sold on the street as a canvas to be painted over, the younger artist instantly recognised Rousseau's genius and went to meet him. In 1908, Picasso held a half serious, half burlesque banquet in his studio at Le Bateau-Lavoir in Rousseau's honour. Le Banquet Rousseau, "one of the most notable social events of the twentieth century," wrote American poet and literary critic John Malcolm Brinnin, "was neither an orgiastic occasion nor even an opulent one. Its subsequent fame grew from the fact that it was a colorful happening within a revolutionary art movement at a point of that movement's earliest success, and from the fact that it was attended by individuals whose separate influences radiated like spokes of creative light across the art world for generations."
Rousseau exhibited his final painting, The Dream, in March 1910, at the Salon des Independants and in the same month suffered a phlegmon in his leg which he ignored. In August he was admitted to the Necker Hospital in Paris where his son had died and was found to have gangrene in his leg.