TWO significant exhibitions opened within a week of each other on either side of the Thames and will run into high summer. At Dulwich, the first show for seven decades of the French Impressionist Berthe Morisot (1841-95) brings some thirty of her paintings together with drawings to explore her debt to the artists of the 18th century.

She had exhibited successfully in the Salon de Paris from the age of 23, but, with the establishment of the Salon des Refusés in 1874, she joined the self-questioning group of “Impressionists”. Moving regularly in their circle, she took part in seven of their eight annual exhibitions. Within months of the opening exposition, she married her friend Édouard Manet’s younger brother, Eugène.

Her only visit to England was her 1875 honeymoon. In London, in the National Gallery, South Kensington, and Manchester House, she first saw the works of British painters, notably Gainsborough, Reynolds, Raeburn, and Romney, artists whom she could not have encountered in the Louvre, which inspired her, alongside the likes of Fragonard and Boucher.

The Manets travelled to the Isle of Wight and stayed at the Globe Cottage during Cowes Week. There she painted a fidgety portrait of her groom beside an open window; the view out over the Parade in West Cowes remains much the same from what is now part of a gastro-pub restaurant.

The raised casement daringly cuts the canvas in half, as a passing nanny and her charge stand by the picket fence. The trip was not a great success; in a newly published letter to her sister, Morisot explained that “Eugène was depressed and I was in a bad temper because I was doing only poor work.”

After the last Impressionist show (1886), which affords the starting point for the exhibition across the river in the National Gallery, she went her own way, abandoning the colourism that had so marked the early Impressionists. By way of an adieu, Dulwich includes a sketchy self-portrait (Musée Marmottan Monet, Paris) from 1885; thereafter, she increasingly used drawings to develop her painted work from squaring-up and enlarging.

The National Gallery takes up the story, tracing the development of art, both in France and more broadly across Europe, until the outbreak of the First World War. It offers us a tour through Brussels, Barcelona, Berlin, and Vienna, with 51 artists and some one hundred works. From further afield come the Norwegian Edvard Munch and Russian-born Kandinsky.

By deliberately avoiding Roger Fry’s useful nomenclature of “Post-Impressionism”, the curators want us to see the two-decade span as one of innovation and of renewal that may have been prompted by Paris’s being the centre of the art world but was no longer defined by it.

This thesis is well sustained, but I was surprised to find neither engagement with the very real social differences between the Austro-Hungarian Empire, the 1874 re-establishment of the Bourbon monarchy in Spain, and the Republic of France, nor reflection on the religion of the century.

To some extent, anti-clericalism, born in the communes of the Revolution, was a French alternative to the spread of Nonconformity in England; but, by the end of the 19th century, it had spawned a new secularism, acutely observed by André Gide in the opening pages of his 1914 novel The Vatican Cellars. Religion and social change are largely ignored here.

The display gets off to a strong start. The walls of the eight rooms are painted a deep blue that makes the most of the paintings; in the first, the Gallery’s own Cézanne Les Grandes Baigneuses, which he worked on for a decade until about 1905, occupies a wall between Rodin’s mammoth 1898 plaster monument of Balzac, which stands 2.75 metres tall, and his bronze The Walking Man of 1905-07 (The Louvre, Abu Dhabi). The headless torso of L’homme qui marche is based on a much earlier cast of St John the Baptist (1878). The figure stands, Stylite-like, on a slender column, feet firmly planted on the Corinthian capital.

Elsewhere, such sculptors as are included — Gauguin, Camille Claudel, George Minne, represented by his Kneeling Youth of the Fountain (MSK Ghent), and Käthe Kollwitz, among them — are served less well by the staging. Gauguin is virtually screened off, and Henri Matisse’s 1907 The Dance is left stranded rather than in dialogue with the dense oil-painting of the same title behind it by the 26-year-old André Derain (1906, private collection): an extraordinary hymn to swirling colour and form.

The second room brings us to the heart of what we know as Post-Impressionism. Intentionally, this show is not as wide-ranging as the RA winter exhibition was back in 1979-80, but much of it feels similar. Van Gogh, Gauguin, Cézanne, and Degas lead the way.

© Musée Marmottan Monet, Paris.Berthe Morisot, Eugène Manet on the Isle of Wight (1885), on loan for the exhibition in Dulwich

There are some choice surprises, with the inclusion of several rarely seen canvases from private collections. Next to Gauguin’s Vision of the Sermon, with the wrestling match of Jacob and the angel viewed in the distance by the Breton women as if they are spectators at a theatrical performance (Edinburgh), and his Fête Gloanec (Orleans), a private loan has secured another of his 1888 paintings, The Wave.

The chromatic link between all three, running across the wall, is the powerful red that forms the ground for the account of Genesis 32, the circular wooden table-top for the still-life, and the astonishing seashore on which two figures seek safety from the force of the incoming wave, viewed from a great height, and appear like black ants, scrabbling across the ground.

The eddying waters and the pronounced rocks begin almost Monet-like, but, as the canvas sweeps to the right, and the waters swirl, the hard red strand appears. We do not need to know that Gauguin had earlier lost both his financial security, in the 1882 Paris Stock Exchange collapse, and his marriage and family a few years later, to explain the intensity of the colour.

Equally instructive, we see Van Gogh’s landscapes of September 1889 (Landscape with Ploughman, private collection) next to his January 1890 homage to the earlier painter Millet (Snow-covered Field with a Harrow, Amsterdam). The brushstrokes used in both, for the land and the sky, appear like turbulent waters in full flood.

The almost life-size group portrait, painted in 1900 by Maurice Denis (1870-1943), depicting artists of the brotherhood Les Nabis, Hommage à Cézanne, was once owned by the Nobel Prizewinner Gide. It makes a powerful statement, hung immediately opposite us, alongside Cézanne’s 1899 portrait of the art dealer Ambrose Vollard, who helped to bank-roll many artists. Vollard’s downward gaze was later picked up on by Picasso (a work not on show).

The men gather in Vollard’s shop on the Rue Lafitte around a still-life that Cézanne had painted in 1879-80 and that was first owned by Gauguin. Still Life with Fruit Bowl was later given by the Rockefellers to the Metropolitan Museum of Art, New York.

Eagle-eyed gallery-goers will recognise it as one of the highlights of the recent Tate Modern exhibition (Arts, 20 January). With Marthe Denis, the art dealer’s wife, the assembled company listen attentively as the 36-year-old red-bearded Paul Sérusier argues a point with the sexagenarian Symbolist Odilon Redon (1840-1916).

By 1900, the Nabi fraternity had all but dispersed, making this painting something of a retrospective work. Of those it depicts, only Édouard Vuillard, Sérusier, and Pierre Bonnard have works in a later room, including Vuillard’s intimate portrayal of his 22-year-old school friend Aurélien-Marie Lugné (1869-1940), reading. Almost as invasive is Toulouse-Lautrec’s painting of his 17-year-old neighbour Hélène Vary, absorbed in her book (1889).

A few years later, in 1895, Lautrec painted his friend the anarchist playwright and filmmaker, Tristan Bernard (1866-1947) standing alone in the middle of the track at one of the velodromes that he owned (ex-catalogue). Turning away from us, he looks over the deserted stands, monarch of all he surveys. It is an awkward but haunting composition. which I first encountered in the 1991 Toulouse-Lautrec winter exhibition at the Hayward Gallery. Later, I saw it on long-term loan (2007-19) at the Metropolitan Museum. Pre-Covid, it was removed by the owner to an auction house, with an ambitious estimate of $US4-6 million; a London auction house sold it in March 2022 for a more realistic £856,800.

The room given to Barcelona highlights Picasso, of course. We find, back to back, painted on reverse sides of the same canvas in 1901, his Woman in the Loge, a sketchy yellow and blue study, and another woman, who stares bleakly out of the frame with a glass of absinthe beside her (on loan to the Kunstmuseum, Basel).

Somewhat older than Picasso were Santiago Rusiñol (1861-1931) and his friend Ramon Casas, born five years later. Both artists were from Catalan bourgeois families. Rusiñol anticipates Picasso’s Blue Period by five years in his portrait of the 40-year-old journalist and writer Modesto Sánchez Ortiz, whose eyes pierce ours, whereas Casas uses the headlights of an automobile to stop us in our tracks.

Like Lautrec, Casas was obsessed with speed and owned one of the first cars in Spain. His is one of a dozen paintings commissioned for the central salon of the privately established (1847) gentlemen’s club El Circulo del Liceo. Whereas the other 11 scenes are scenes in the theatre and backstage, this canvas shows an independent woman driving off after an evening out: Freedom and Modernism from a world that Morisot helped to shape.

“Berthe Morisot: Shaping Impressionism” is at Dulwich Picture Gallery, Gallery Road, London SE21, until 10 September. Phone 020 8693 5254. www.dulwichpicturegallery.org.uk

“After Impressionism: Inventing Modern Art” is at the National Gallery, Trafalgar Square, London, until 13 August. Phone 020 7747 2885. www.nationalgallery.org.uk