Two color-printed Mezzotints from  Johann Weinmann’s “Floral Studies” c.1736.

The method of mezzotint was invented in the mid 17th century. Ludwig von Siegen was credited to be the original mezzotint printmaker, though he did not use the proper tool, known as a rocker. Prince Rupert created the tool when he was exiled to Holland. His assistant, Wallerant Vaillant, was a professional printmaker who perfected the technique. Since Vaillant settled in Holland, it became the primary location for early mezzotint. France, Germany, and Holland all established markets for Mezzotints by late 1660. By 1670, mezzotint was being introduced in London and became fully adopted by British printmakers by 1680. It became popular among portraitists because of the amount of detail. To see more about the process behind this technique, watch the video below.

 
Sepia Mezzotints from Claude Lorraine’s “Beauties of Claude Lorraine” c.1825

Source: https://www.npg.org.uk/research/programmes/early-history-of-mezzotint/#anchor96338