The Harley Gallery at the Welbeck Estate in Nottinghamshire is due to reopen on 20 March with an 800 sq. m expansion designed by Hugh Broughton Architects. A new gallery will display works from the collection, including the pearl earring that Charles I wore to his execution in 1649 and Michelangelo’s drawing Madonna del Silenzio (around 1538), which has not been on show for 50 years. The inaugural exhibition has been organised by the artist Peter Blake and presents miniature portraits by artists including the Renaissance painter Nicholas Hilliard. The gallery declined to specify the cost of the project.