Prince Rupert was a nephew of Charles I and served as a commander of the Royalist cavalry during the English Civil War. He was also a scientist and a pioneer of mezzotint, a technique that he learned while in exile during the Interregnum, probably from its inventor Ludwig von Siegen. Rupert produced at least fifteen mezzotints, of which the Great Executioner is the most ambitious, based ultimately on a painting of the beheading of the Baptist by Jusepe de Ribera (called Lo Spagnoletto, hence the inscription Sp. In[venit].). Rupert’s reduced version of this print, bound in to John Evelyn's Sculptura of 1662, was the first mezzotint published in England.