In 1660, following the Restoration of the Monarchy, Prince Rupert returned to England, bringing with him the new art of mezzotint. The following year, this treatise on printmaking by John Evelyn stated that a ‘new way of Engraving, or Mezzo Tinto’ was ‘Invented, and communicated by his Highness Prince RUPERT…’. This slightly later edition of Evelyn’s treatise, dating from 1662, contains a small mezzotint by Prince Rupert, known as the Little Executioner. Although it is now known that Prince Rupert did not invent the art of mezzotint, as claimed by Evelyn, he introduced it to England, and in addition he invented the mezzotint rocker – a wide curved tool with teeth, used to roughen the copper plate with thousands of dots, which allowed the half-tones to be created. In 1668 Prince Rupert was appointed Governor and Constable of Windsor Castle, where he spent his final years until his death in 1682. He resided in the Round Tower, where his apartments included a laboratory, forge, workshop and library