The preparatory sketch, which had been in a private collection in the US for many years, was previously unknown to Constable scholars.
Estimated at £200,000-300,000, it generated strong pre-sale interest and was eventually sold to a telephone bidder.
Bonhams’ director of Old Master paintings Andrew McKenzie described the 7 x 10in (18 x 25cm) oil sketch as “a Constable masterpiece in miniature”.
Entitled Flatford Lock on the Stour looking towards Bridge Cottage, the work was made in preparation for Landscape: Boys Fishing, the artist’s submission to the Royal Academy in 1813. It depicts Flatford Lock, one of Constable’s favoured sites – his father owned Flatford Mill – which he depicted in works now in the collections of the Victoria and Albert Museum, the Tate and the Royal Academy.
Bonhams said the re-emergence of this sketch had made a “major contribution” to understanding the genesis of the finished painting, which is now in a poor state of preservation.
The sketch was originally in the collection of Isabel Constable, the artist’s daughter, and then is thought to have been included either in the sale of her estate in 1891 and ’92 or in her bequests to her nephews. It was subsequently purchased by collector Victoria Bray in the early 1940s and passed by descent on her death in 1961 to the consignor.
“I am not surprised that this exquisite work commanded such a high price,” said McKenzie.