The Samian Sibyl with a Putto

Guercino painted this in 1651 because the first picture meant for the commission had gone elsewhere. Giuseppe Locatelli of Cesena had ordered a companion for his King David, and when that canvas was sold to another buyer, the painter started again with a new figure. The Samian Sibyl is named after the Greek island of Samos. She was a priestess of Apollo, believed by Christians to have foretold that Christ would be born of a virgin, which is what the putto's scroll announces. Guercino makes her a reader, head propped on one hand, an elbow on a closed book as she turns the pages of another. In 1768 the Scottish painter and dealer Gavin Hamilton bought the picture for John Spencer, the first Earl Spencer. It stayed with his family, in London and then at Althorp in Northamptonshire, until 2012.