Many cities claim to be the Venice of the North, but Portsmouth is not always the first in line in that respect.

But it now appears that art lovers who for decades have been admiring J.M.W. Turner’s festival scenes of Venice, have actually been looking at two views of a French king’s visit to Portsmouth.

As part of the preparation for a major new exhibition at Tate Britain, Collections Curator Ian Warrell, looked closely at two oil paintings of the Venetian lagoon and has now asserted that the works actually depict the South Coast of England.

As a result, the painting formerly listed as Festive Lagoon Scene, Venice circa 1840-50 has now been renamed The Arrival of Louis-Philippe 8 October 1844, circa 1844-5, and Procession of Boats with Distant Smoke, Venice circa 1845 has been renamed The Disembarkation of Louis-Philippe at Portsmouth 8 October 1844, circa 1844-5.

In the catalogue notes accompanying the exhibition, Mr Warrell said that the Procession of Boats, previously known as The Burning of Ships, was first specifically linked with Venice in the mid-1960s at an exhibition in New York, while the other picture came to light in a cache of works unearthed in the National Gallery’s basement in World War II.

Among the reasons Mr Warrell doubted the link to Venice were the fact that there were no obvious topographical or architectural references to the Italian city, the canvases were considerably bigger than the series which clearly showed the Venetian skyline, and the tones of the two Portsmouth pictures are considerably warmer than the grey tonality of the Venetian series.

There is also a row of what appears to be military men in red, which would tend to suggest British soldiers at a formal occasion – and it is known that Turner was there when Louis-Philippe visited Portsmouth, and produced a group of studies related to the occasion.

The artist also knew Louis-Philippe personally from when the French aristocrat lived in Twickenham.

According to Mr Warrell, the French king visited Portsmouth aboard his paddle-steamer the Gomer as part of an initiative to consolidate an alliance with Queen Victoria. As the Gomer arrived – in a series of ceremonies widely reported in the British press – gun salutes were fired which caused smoke to build up over the anchorage, and people thronged to the beaches to watch proceedings.

Mr Warrell concludes: “This is all a long way from the interpretation of these pictures as the wraith-like mists of Venice, with parties of revellers drifting to and from the city across the Lagoon.

“But it demonstrates the way in which Turner’s vision of Venice relies less on the specifics of place, and far more on what he brought to the scene.

“Whether he was painting Venice or the Solent, he remained obsessed with the elusive qualities of light and colour, and it is his restless exploration of these characteristics that continue to captivate.”

Both pictures will still feature in the exhibition Turner and Venice, sponsored by Barclays plc, which opens at Tate Britain on October 9 and runs until January 11 2004.

It covers the 20 years between Turner’s first visit to Venice in 1819 and his last in 1840, and brings together some 55 oil paintings and more than 100 watercolours, as well as prints, maps and Turner’s Venice sketchbook.

The exhibition is set out as a city tour of Turner’s Venice staring at the Doge’s Palace and the San Marco basilica, then moving into the surrounding districts.