License, verbatimPD
The National Gallery of Art: open access image with no usage restrictions under the NGA's open access policy (openaccess=1 in the Gallery's published_images dataset).
Matteo de' Pasti. Isotta degli Atti, 1432/1433-1474, Mistress 1446, then Wife after 1453, of Sigismondo Malatesta [obverse], c. 1450. National Gallery of Art, Washington.