Matisse went to Paris to study law, working as a court administrator in Le Cateau-Cambrésis after gaining his qualification. He first started to paint in 1889, after his mother brought him art supplies when he was recovering from an attack of appendicitis. He discovered "a kind of paradise" as he later described it, and decided to become an artist, deeply disappointing his father, who wanted him to become a lawyer.
In 1891 he returned to Paris to study art. At first, he painted still lifes and landscapes in a traditional style, which he was quite good at. Matisse was influenced by the works of earlier masters such as Jean-Baptiste-Siméon Chardin, Nicolas Poussin, and Antoine Watteau, as well as by modern artists, such as Édouard Manet, and by Japanese art. Chardin was one of the painters Matisse most admired. While studying art he made copies of four of Chardin's paintings. In 1896 and 1897, Matisse visited the Australian painter John Peter Russell on the island Belle Île off the coast of Brittany. Russell introduced him to Impressionism and to the work of van Gogh, who had been a friend of Russell but was completely unknown at the time. Matisse's style changed completely. He later said "Russell was my teacher, and Russell explained colour theory to me." In 1896 Matisse exhibited five paintings, two of which were purchased by the state.
He had a daughter, Marguerite, born in 1894 and in 1898 he married Amélie Noellie Parayre. Together they raised Marguerite together and had two sons. Marguerite and Amélie often served as models for Matisse. In 1898 he went to London to study paintings and upon his return to Paris in February 1899, he worked beside Albert Marquet and met André Derain, Jean Puy, and Jules Flandrin. Matisse immersed himself in the work of others and went into debt from buying work from painters he admired. In Cézanne's sense of pictorial structure and colour, Matisse found his main inspiration. Many of Matisse's paintings from 1898 to 1901 make use of a Divisionist technique he adopted after reading Paul Signac's essay, "D'Eugène Delacroix au Néo-impressionisme". His paintings of 1902 to 1903 are comparatively somber and reveal a preoccupation with form. Around April 1906, Henri Matisse met Pablo Picasso, who was 11 years younger than him. The two became lifelong friends as well as rivals and are often compared. One key difference between them is that Matisse drew and painted from nature, while Picasso was much more inclined to work from imagination. But both of the artists mainly painted were women and still life.
Fauvism as a style began around 1900 and continued beyond 1910. The movement as such lasted only a few years, 1904–1908, and had three exhibitions. The leaders of the movement were Matisse and André Derain. Matisse's fondness for bright and expressive colour became more pronounced after he spent the some time in 1904 painting with the neo-Impressionists Signac and Henri-Edmond Cross. In that year he painted the most important of his works in the neo-Impressionist style. In 1905 he travelled southwards again to work with André Derain at Collioure.
Matisse and a group of artists now known as "Fauves" exhibited together in a room at the Salon d'Automne in 1905. The paintings expressed emotion with wild, often dissonant colours, without regard for the subject's natural colours. Matisse was recognised as a leader of the Fauves, along with André Derain; the two were friendly rivals, each with his own followers. The Symbolist painter Gustave Moreau (1826–1898) was the movement's inspirational teacher. As a professor at the École des Beaux-Arts in Paris, he pushed his students to think outside of the lines of formality and to follow their visions.
The decline of the Fauvist movement after 1906 did not affect the career of Matisse. He continued to absorb new influences. Matisse travelled from 1906 to 1913, to study different forms of art. These travels effected his artworks because he found new influences.The effect on Matisse's art was a new boldness in the use of intense, unmodulated colour.
In 1917 Matisse relocated to a suburb of the city of Nice. His work of the decade or so following this relocation shows a relaxation and a softening of his approach. After 1930 a new vigor and bolder simplification appeared in his work. American art collector Albert C. Barnes convinced him to produce a large mural for the Barnes Foundation, The Dance II, which was completed in 1932. This move toward simplification and a foreshadowing of the cutout technique are also evident in some of his other works.
Matisse's wife Amélie, who suspected that he was having an affair with her young Russian emigre companion, Lydia Delectorskaya, ended their 41-year marriage in July, 1939, dividing their possessions equally between them. Delectorskaya attempted suicide by shooting herself in the chest.
Matisse was visiting Paris when the Nazis invaded France in June, 1940, but managed to make his way back to Nice. His son, Pierre begged him to leave Nice while he could. Matisse was, in fact, about to embark for Brazil to escape, but abruptly changed his mind and stayed in Nice. “It seemed to me as if I would be deserting,” he wrote Pierre in September, 1940. “If everyone who has any value leaves France, what remains of France?” Although he was never a member of the resistance, it became a point of pride to the occupied French that one of their greatest artists chose to stay. While the Nazis occupied France from 1940-1944, Matisse was allowed to exhibit along with other former Fauves and Cubists whom Hitler had initially claimed to despise, though without any Jewish artists, all of whose works had been purged from all French museums and galleries. Any French artists exhibiting in France had to sign an oath - including Matisse.
In 1941, Matisse was diagnosed with duodenal cancer. The surgery, while successful, resulted in serious complications from which he nearly died. Being forced to stay in bed for three months, resulted in him developing a new art form using paper and scissors. Matisse remained for the most part isolated in southern France throughout the war. Nonetheless, his family was intimately involved with the French resistance. His son Pierre, the art dealer in New York, helped the Jewish and anti-Nazi French artists he represented to escape occupied France and enter the United States. Matisse was shocked when he heard that his daughter Marguerite, who had been active in the Résistance during the war, was tortured (almost to death) by the Gestapo in a Rennes prison and sentenced to the Ravensbrück concentration camp in Germany. Marguerite managed to escape and she survived in the woods in the chaos of the closing days of the war, until rescued by fellow resisters.
Diagnosed with abdominal cancer in 1941, Matisse underwent surgery that left him chair and bed bound. Painting and sculpture had become physical challenges, so he turned to a new type of medium. With the help of his assistants, he began creating cut paper collages, or decoupage. He would cut sheets of paper, pre-painted with gouache by his assistants, into shapes of varying colours and sizes, and arrange them to form lively artworks. These paper cut-outs were Matisse’s major medium in the final decade of his life. He moved to the hilltop of Vence in 1943, where he produced his first major cut-out project called Jazz. The number of self made cut-outs steadily increased following Jazz, and eventually led to the creation of mural-size works, such as Oceania the Sky.