Pictures, books and ephemera from the Great Tew estate in Oxfordshire will be offered for sale at Holloway’s in Banbury on July 10.

They include this 18th century English school oval portrait silhouette of the pioneering manufacturer Matthew Boulton (1728-1809).

The 5¼ x 4in (13 x 10cm) black gouache over pencil silhouette on an orange ground is inscribed Boulton of Soho House - a reference to Boulton's home of 43 years in Handsworth, Birmingham.

The source of the miniature, recently unearthed in one of the estate buildings, is not surprising: Matthew Boulton's son Matthew Robinson Boulton (1770-1842) bought Great Tew in 1815, famously commissioning London cabinetmaker George Bullock (1777-1818) to furnish the main house.