An eighteenth-century drawing by the Venetian master Giovanni Battista Tiepolo (1696-1770) is heading to auction after it was discovered in a loft.

The pen and ink drawing was found in Weston Hall, Northamptonshire and will go under the hammer with its contents at the sale: ‘Weston Hall and the Sitwells: A Family Legacy’. Auctioneers believe the drawing could fetch between £150,000 and £250,000.

Henrietta Sitwell, whose family have owned Weston Hall for 300 years, said “as I peeled back the wrapping, I instantly recognised it as something special.” The artwork had laid undisturbed for over 80 years, until the descendants began clearing out the loft. “It was thrilling to think that such a captivating and important work of art by such a revered Old Master was just lying there gathering dust over the years,” she added.

Inspired by the masters of the High Renaissance, Tiepolo became one of the greatest Italian Rococo painters of his time. He was a prolific artist, working alongside his son Giovanni Domenico Tiepolo (1727-1804) across Italy, Germany and Spain. Tiepolo’s drawings expressed his unbridled creativity, exploring a range of themes from interior decorative schemes, religious imagery, and caricatures.

The Weston Hall drawing depicts a large group of Punchinello, hook-nosed, humpbacked clowns whose character originates from a popular theatre in seventeenth-century Naples, the commedia dell’ arte. Tiepolo and his son were fascinated by the character, drawing them extensively in all sorts of predicaments. Here, the mischievous Punchinello are suffering the consequences of their gluttony after eating too many gnocchi.

“The re-discovery of the work by Tiepolo has probably been the most important find of the auction and we are delighted to be offering it for sale for the first time in over 80 years,” remarked Joe Robinson, Head of House Sales and Private Collections at Dreweatts. “Walking through the attics was like uncovering an Egyptian tomb, with wonderful things emerging from layers of dust.”

In 1936, Tiepolo’s work was acquired by the writer Osbert Sitwell (1892-1969), Henrietta’s great-uncle, at the Henry Oppenheimer (1859-1932) sale of Old Master Drawings at Christie’s. The Sitwell family have owned the grade II listed manor house since 1714. Complete with 49 acres of gardens, tennis courts and a swimming pool, the house is up for sale for £3.25 million.

The current owner of the house is William Sitwell, the renowned food critic and MasterChef judge. Speaking about the sale of his ancestral home, Sitwell said “given my personal attachment to Weston Hall, and my family’s link to the property since 1714, saying goodbye is terribly sad and a wrench, but whoever the future owner is will find that it’s wonderful in so many ways.”

The auction will take place on 16 and 17 November at Donnington Priory in Berkshire.