There has been a small but fascinating exhibition tucked into the National Gallery rooms in London. "Forest, Rocks, Torrents. Norwegian and Swiss Landscape Paintings from the Lunde Collection" had just opened when I saw it in late June but it runs until the 18th September.

Two rooms, but expansive views of Norwegian and Swiss mountains, rivers and dramatic natural scenery that take one far away from the tourist-filled Trafalgar Square outside. It was a collection of small and beautiful paintings assembled by Asbjorn Lunde, a major art collector/lawyer from New York. Not only did this exhibition of art delight and inform, but it made me think about the role of landscape painting in national politics and national identity. This was mainly because of a fascinating and informative piece, "Two Traditions", in the catalogue written by Christopher Riopelle. Curator of post-1800 Painting at the National Gallery.

Ancient Rome celebrated its landscapes in frescoes, such as those which survived from Pompeii. However, in the Western art tradition, basically relgious motifs and classical narratives provided the major impetus for painting themes and subjects until the 17th century. At that time, the Dutch begain to celebrate their flat, luminous countryside, where the northern light and ever-present sea predominated. They had regained control of their land (and church) from the Spanish and by the 17th century, Holland was linking political identity with the Dutch landscape. In fact, the very word landscape, used in relationto painting, comes from the Dutch language, where landschap first meant a cultivated patch of land and then an image.

Jacob van Ruisdael was a major protagonist of Holland's land and wide skies in his art in the 17th century, as one can judge in this "View of Harlem", above. Much of this landscape art was produced in studio after plein air studies had first been done.

Salomon van Ruysdael specialised more in maritime scenes, but he too represented the Dutch landscape in remarkable fashion.

These and many other artists were projecting the new self-confidence of a successful maritime nation whose trading stretched across the globe and brought home great wealth. These relatively small landscape paintings were bought by the affluent burghers as part of this new national celebration.

The same phenomenon occurred in Britain in the 18th century as the landed gentry and newly-affluent townspeople started to identify with their green, gentle island whose power was spreading far abroad. There were many great landscape artists working then, and even those more famous for portraiture, such as Thomas Gainsborough, were meeting this demand for landscapes. His 1748 "Landscape in Suffolk" is one such example. In subsequent decades, John Constable and J.M.W.Turner, amongst other artists, also allowed the English to be proud of their island, its landscapes, people and history, through their paintings.

Constable painted this canvas of "Harwich Lighthouse" about 1820. His renditions of skies and clouds show the results of his many, many wonderful cloud studies and knowledge of Britain's climatic conditions.

Turner was equally attentive to light and climate as he painted, as can be judged by this astonishing canvas from 1816, "Chichester Canal". Apparently, the Indonesian volcano, Mt. Tambora, had erupted very violently in 1815, and the ash travelled around the world, causing dramatic atmospheric conditions. The 3rd Earl of Egremont commissioned the painting.

While the British, the Russians, the Swiss, the Norwegians and other Europeans were identifying increasingly with their nations, thanks in large part to artists' depictions of the natural wonders and characteristics, the Americans were doing the same. As the Hudson River School, the Romantic and Luminist schools of landscape painters developed in the United States, the paintings of the country's natural splendours helped fuel the sense of nationhood and drive towards development of the West. Even the eventual creation of National Parks was made easier by the depictions of the marvels of Yosemite and Yellowstone. Manifest destiny was implicit in much of the 19th century landscape painting in America, where discovery, exploration and settlement were all driving forces in society.

British-born American artist Thomas Cole was the founder of the Hudson River School; he introduced the beauties of the Hudson River Valley, the Catskill Mountains and upper New York/New England to an audience of appreciative fellow Americans. Second generation American landscape painters who continued to shape the political framework of America included such artists as Luminist John Frederick Kennsett. His work centered on the North East, but included work depicting the Mississippi and further afield.

Thomas Moran, meanwhile, was celebrating the wonders of the West. His depictions of Yellowstone were hugely instrumental in the National Park being created. His dramatic canvases were complemented by watercolours of many natural phenonmena, such as this 1873-74 watercolour of the "Shoshone Falls, Idaho" (image courtesy of the Chrysler Museum of Art).

All these landscape artists, European, Russian, American... were part of an ever-swelling political discourse about national identity and aspirations. The 18th and 19th centuries were era of great social upheavals and changes, with the Industrial Revolution shaping new societies. With increasing urbanisation, the role of landscape underwent a subtle change: it was no longer such an important defining factor in perception of nation. Artists themselves were often urban dwellers who had to make trips to the countryside to paint landscapes. The French Impressionists built on this tendancy that the previous generation of artists had begun - from Daubigny to Millet and Rousseau. Monet, Pissarro, Sisley, and their companions all made trips out from Paris in their early times as artists. But they also found increasing inspiration in urban scenes - railway stations, the French boulevards, the Seine river. As the artistic trends evolved, Picasso, Braque, Juan Gris, Matisse and countless others began to turn away from landscape painting. There were, of course, others - Cezanne, the Fauves, Miró  - who still used the vocabulary of landscape to explore the role of man in society.

Nonetheless, I can't help wondering how much the influence of urban landscapes - concrete and stone boxes and towers, streets vanishing in distant perspectives, the geometry of man's creations - overwhelmed the artistic eye as the trend accelerated towards abstraction and away from organic natural shapes and scenes. With such a different artistic vocabulary, has our societal identification of land and nation altered? Even though today's world is saturated with high definition images of amazing landscapes, do we identify with our lands in the same way as people did in previous centuries with their artists' depictions of land/nation? Do we find it easier to airbursh/Photoshop ourselves out of involvement with the landscapes we are filling up and polluting and exhausting today? Easier than when we were being shown the beauties of our lands by artists who were, in essence, pictoral ambassadors for those splendors? Indeed, basically, the majority of today's populations live in some form of urban setting, where concrete obliterates the natural world and where political perceptions have been altered by those surroundings.

Today's landscape artists have a very different role, I suspect, from the nation-building one of the Dutch artists onwards. Now, perhaps, it is almost a rearguard action or one of recording natural beauties before they disappear. However, I have grave doubts as to whether any of today's landscape artists, seldom ones who make the headlines in the art world, have much sway amongst our politicians. Perhaps it would make society better if they did?