Like Courbet, Edouard Manet (1832-83) was strongly influenced by Spanish painters, whose works had become more easily accessible to artists when a large collection belonging to the Orléans family was confiscated by the state in 1848. Unlike Courbet, though, he never saw himself as a socialist or indeed as a rebel or avant-garde painter, yet his technique and interpretation of themes was quite new and shocked as many people as it inspired. Manet used bold contrasts of light and very dark colours, giving his paintings a forcefulness that critics often took for a lack of sophistication. And his detractors saw much to decry in his reworking of an old subject originally treated by the sixteenth-century Venetian painter, Giorgione, Le Déjeuner sur l'Herbe . Manet's version was shocking because he placed naked and dressed figures together, and because the men were dressed in the costume of the day, implying a pleasure party too specifically contemporary to be "respectable".

Manet was not interested in painting moral lessons, however, and some of his most successful pictures are reflections of ordinary life in bars and public places, where respectability, as understood by the late nineteenth-century bourgeoisie, was certainly lacking. To Manet, painting was to be enjoyed for its own sake and not as a tool for moral instruction - in itself an outlook on the role of art that was quite new, not to say revolutionary, and marked a definite break with the paintings of the past. With Manet, the basis of our present expectations and understanding of modern art was established.

From the 1870s, Manet began to adopt the Impressionist techniques of painting out-of-doors, and his work became lighter and freer. Although it is doubtful whether Manet either wanted or expected to assume the role of leader, he found himself a much-admired member of that group of painters, one of whom was Claude Monet (1840-1926). Born in Le Havre, Monet came in contact with Eugène Boudin (1824-98), whose colourful beach scenes anticipated the way the Impressionists approached colour. He then went to Paris to study under Charles Gleyre, a respected teacher in whose studio he met many of the people with whom he formulated his ideas. Monet soon discovered that, for him, light and the way in which it builds up forms and creates an infinity of colours was the element that governed all representations. Under the impact of Manet's bright hues and his unconventional attitude, ("art for art's sake"), Monet soon began using pure colours side by side, blended together to create areas of brightness and shade.

In 1874, a group of some thirty artists exhibited together for the first time. Among them were some of the best-known names of this period of French art: Degas, Monet, Renoir, Pissarro. One of Monet's paintings was entitled Impression: Sun Rising , a title that was singled out by the critics to ridicule the colourful, loose and unacademic style of these young artists. Overnight they became, derisively, the "Impressionists".

Camille Pissarro (1830-1903) was slightly older than most of them and seems to have played the part of an encouraging father-figure, always keenly aware of any new development or new talent. Not a great innovator himself, Pissarro was a very gifted artist whose use of Impressionist technique was supplemented by a lyrical feeling for nature and its seasonal changes. But it was really with Monet that Impressionist theory ran its full course: he studied endlessly the impact of light on objects and the way in which it reveals colours. To understand this phenomenon better, Monet painted the same motif again and again under different conditions of light, at different times of the day, and in different seasons, producing whole series of paintings such as Grain Stacks, Poplars and, much later, his Waterlilies . In the late 1870s and the early 1880s many other artists helped formulate the new style, though few remained true to its principles for very long.

Auguste Renoir (1841-1919), who started life as a painter of porcelain, was swept up by Monet's ideas for a while, but soon felt the need to look again at the old masters and to emphasize the importance of drawing to the detriment of colour. Renoir regarded the representation of the female nude as the most taxing and rewarding subject that an artist could tackle. Like Boucher in the eighteenth century, Renoir's nudes are luscious, but rarely, if ever, erotic. They have a healthy, uncomplicated quality that was, in his later paintings, to become cloyingly, almost overpoweringly, sickly and sweet. Better were his portraits of women fully clothed, both for their obvious and innate sympathy and for their keen sense of design.

Edgar Degas (1834-1917) was yet another artist who, although he exhibited with the Impresssionists, did not follow their precepts very closely. The son of a rich banker, he was trained in the tradition of Ingres: design and drawing were an integral part of his art, and, whereas Monet was fascinated mainly by light, Degas wanted to express movement in all its forms. His pictures are vivid expressions of the body in action, usually straining under fairly exacting circumstances - dancers and circus artistes were among his favourite subjects, as well as more mundane depictions of laundresses and other working women.

Like so many artists of the day, Degas had his imagination fired by the discovery of Japanese prints , which could for the first time be seen in quantity. These provided him with new ideas of composition, not least in their asymmetry of design and the use of large areas of unbroken colour. Photography , too, had an impact, if only because it finally liberated artists from the task of producing accurate, exacting descriptions of the world.

Degas' extraordinary gift as a draughtsman was matched only by that of the Provençal aristocrat Henri de Toulouse-Lautrec (1864-1901). Toulouse-Lautrec, who had broken both his legs as a child, was unusually small, a physical deformity that made him particularly sensitive to free and vivacious movements. A great admirer of Degas, he chose similar themes: people in cafés and theatres, working women and variety dancers all figured large in his work. But, unlike Degas, Toulouse-Lautrec looked beyond the body, and his work is scattered with social comment, sometimes sardonic and bitter. In his portrayal of Paris prostitutes, there is sympathy and kindness; to study them better he lived in a brothel, revealing in his paintings the weariness and sometimes gentleness of these women.