Turner's German masterpiece to be auctioned in London

Ehrenbreitstein is one of only six major paintings by the artist still in private hands and has an estimate of £15m-£25m

Detail from Turner's Ehrenbreitstein (1835)
Detail from Ehrenbreitstein. The painting was considered a showstopper when first exhibited in 1835. Photograph: Sotheby's

Turner's German masterpiece to be auctioned in London

Ehrenbreitstein is one of only six major paintings by the artist still in private hands and has an estimate of £15m-£25m

One of the finest paintings by JMW Turner still in private hands is to be auctioned in London.

Ehrenbreitstein, showing a magnificent ruined fortress perched on a cliff overlooking a tranquil valley, was considered something of a showstopper when first exhibited at the Royal Academy in London in 1835.

Today it is one of only six major Turner paintings owned privately and is, the auction house Sotheby’s said, considered the most important oil painting of a German subject that the artist ever painted.

The painting, with its full title of Ehrenbreitstein, or The Bright Stone of Honour and the Tomb of Marceau, from Byron’s Childe Harold, was first shown alongside four others at the RA.

“Of those five paintings, it was Ehrenbreitstein that caught the imagination of public and critics alike,” said Alex Bell, the co-chairman of Sotheby’s old masters department. “And it’s easy to see why.”

Bell said the range of colour and use of light marked it out as a masterpiece, “but its true greatness lies in the way Turner applies his painterly genius to transform the ruins of the famous fortress into a poetic and symbolic image as resonant then as it is today”.

For obvious reasons, major Turners are rare on the market. The last example was Rome, from Mount Aventine, which sold for a record £30.3m in 2014 – the highest price ever achieved for any British-born artist at auction. Ehrenbreitstein has an estimate of £15m-£25m.

The other paintings in the 1835 show are all now in public collections: Keelmen Heaving in Coals by Moonlight is at the National Gallery of Art, Washington DC; Venice, from the Porch of Madonna della Salute is in New York’s Metropolitan Museum of Art; Line Fishing off Hastings is in the V&A in London; and The Burning of the Houses of Lords and Commons is at the Cleveland Museum of Art in Ohio.

Ehrenbreitstein was considered the best of them all by the public and critics with the correspondent for the Spectator calling it “a splendid tribute of genius to one of the champions of freedom”.

The painting will go on display in Cologne, Germany, on Wednesday before it is shown in Los Angeles, New York, Hong Kong and Paris ahead of its sale in London on 5 July.