Marcantonio Raimondi was an Italian engraver, known for being the first important printmaker whose body of work consists mainly of prints copying paintings, some of which include works by Dürer, Michaelangelo and Raphael. As such, he is considered to be a key figure in the rise of the reproductive print and he systematized a technique of engraving that became dominant in Italy and beyond.
Caesar Borgia was an Italian condottiero, nobleman, politician and cardinal. He appointed Leonardo da Vinci as military architect and engineer and tasked him with the inspection and direction or all ongoing and planned construction in his domain.
Two later versions of the present miniatures, dated 1805 are listed in R. Walker 'Henry Bone's Pencil Drawings in the National Portrait Gallery', The Walpole Society, 1999, LXI, p. 335, no. 340 and p. 316, no. 65, respectively. According to their inscriptions, they were made for Lord Radstock. They were later sold in his sale, Christie's, London, 13 May 1826, lots 3 and 4. The preparatory drawings by Bone, dated 1802 and 1801, respectively, are in the National Portrait Gallery, London (inv. nos. D17414 and D17409).