Family sells its £7m Turner to pay for Sudeley Castle repairs

This painting of the Thames by JMW Turner is to be sold at auction for an estimated £7 million to help shore up the future of one of England's finest castles.

The oil masterpiece shows the rundown villa of Turner's hero and inspiration, the poet Alexander Pope, as viewed from nearby Strawberry Hill.

It has hung on public view at Sudeley Castle in Gloucestershire for almost four decades. The 15th century castle was once home to Catherine Parr, the sixth of Henry VIII's wives, and Lady Jane Grey.

Its chatelaine is now Lady Ashcombe, who shares it with her art dealer daughter Mollie Dent-Brocklehurst and her son Henry Dent-Brocklehurst, his former model wife Lili Maltese and the couple's two sons.

The painting has been in the family for almost two centuries, but is being sold to pay for development of the castle.

A BBC4 fly-on-the-wall documentary filmed last year revealed that despite income from hiring the castle out for weddings and events - in 1997 Elizabeth Hurley, a family friend, married Arun Nayar at its chapel - the castle is losing £100,000 a year.

At the time Lady Ashcombe said the family might even be forced to sell up.

Emmeline Hallmark, Sotheby's head of British paintings, said the Turner is a beautiful work and one of only 20 of his masterpieces still left in private hands. It has come to auction only once before, in 1827.

Miss Hallmark said: "It is incredibly rare to find something that hasn't been on the open market for 180 years.

It is so different from anything that has appeared in living memory. It was painted as he was formulating his revolutionary approach to painting."

The huge work, Pope's Villa At Twickenham, was first exhibited in the gallery Turner had opened specifically to promote landscapes which he believed were unappreciated.

The state of Pope's villa was seen as a scandal at the beginning of the 19th century when the then owner planned to demolish it to create a new home, partly out of exasperation at the poet's fans who turned up to pay homage.

Turner lived nearby at the time and was appalled.

"He responded to the fact that somebody could be so brazenly unappreciative of Pope and his heritage and legacy," Miss Hallmark said.

The painting was produced shortly after the artist was elected the professor of perspective at the Royal Academy in 1807. It is thought to be the first signed with an additional "pp".

The work was bought at auction in 1827 by James Morrison, an entrepreneur and collector. It descended through his family to Mary Morrison who married Major John Dent-Brocklehurst, of Sudeley Castle, in 1924. He died in 1972, but his widow, and their children took over responsibility for the home.

The record for a Turner oil is the £20.5 million paid two years ago for a view of Venice called Giudecca, La Donna Della Salute And San Giorgio. Pope's Villa At Twickenham will be sold in London on 9 July.