Although large swathes of East Anglia's ever-eroding coastline are now officially abandoned to the elements, this year cranes and barges have been busy shoring up Southwold Harbour after a long local campaign. And just below the southern, Walberswick side of a haven bristling with fishing boats, a broken line of weeded stumps bared at low tide like a primeval seahenge reveals the route to a former pierhead. Here, a parade of promenading girls prompted some of the most beautiful paintings in the history of British art.

Swept away by Edwardian redevelopment, that pier had set the stage for daring, dazzling and much-derided pictures by Philip Wilson Steer (1860-1942) who, fresh from France, created some of the first and finest experiments in English Impressionism in this rather unlikely eastern refuge. They ran for a decade from 1884 before the restless artist himself tan away--retreating into safer worlds of distant reaction. Why did his art blaze with such an incendiary brightness on the Suffolk coast that it left what we can now recognise as a pall of dust and a taste of ashes over the rest of his career? There are tantalising clues in the place and the pictures.

But, very clearly, an obituary has rarely proved more premature than the notice printed in an 1881 edition of The Etcher. Alongside what appeared to be valedictory views of Southwold Harbour by Theodore Dalgliesh and Charles Keene, a deathly commentary announced that the silting of the River Blyth and arrival of the railway had finished off this remote spot as a fertile sketching ground. Such a black and white verdict then went on to mourn a lack of colour along the Walberswick bank due to the tarred roofs of the fishermen's shacks.

Punch illustrator Charles Keene was a masterly draughtsman whose work was admired by Monet and Pissarro and collected by Degas. He was a close friend and sketching companion of etcher Edwin Edwards, who often visited Paris and when at home in Sunbury-on-Thames with his formidable wife, Ruth, presided over a salon that attracted the likes of Whistler, Manet and Fantin-Latour-the latter's Portrait of Mr and Mrs Edwards, from 1875, is now in the National Gallery, London. In avant-garde art circles, word about Walberswick was quietly spreading even as its demise was declared. And in 1881, the lately laid, narrow gauge railway track from Halesworth to Southwold--more twig line than branch line--helpfully added an extra stop in the heath behind the coastal village the locals called 'Wobbleswick', and where artists soon alighted from all over Britain and beyond to form a seasonal seaside colony.

The annual invasion began in 1884 with the arrival of radical young painters who, returning from studies in Paris or Antwerp, wanted to build on their liberating lessons by working directly in front of nature (two years later they would join forces in the New English Art Club). St Ives and Newlyn in the far west of Cornwall were rival magnets--especially for those who had spent recent summers...