Johann Georg Holtzhey

According to the Netherlands Institute for Art History (RKD) he was the son of Martin Holtzhey, master of the mint in Gelderland and Middelburg.

[2] Another receipt in the archive of Teylers Stichting testifies to the great care Holtzhey took when sending the medals, which were securely packed in wool to protect them from shaking.

The reverse shows the unicorn of the Royal coat of arms of the United Kingdom, prostrate with its horn broken against a rock cliff.

The inscription reads, “Tyrannis virtute repulsa / sub Galliae auspiciis,” which translates to “Tyranny repelled by valor / under the auspices of France”,[5] Though Adams wrote ironically to his wife Abigail of the Dutch love for medals as a method of celebrating events, he wrote very respectfully to Holtzhey himself and thanked him for his work and explanation of the designs.

[7] Though he married twice he remained childless, and he was succeeded as mint master in Utrecht by his pupil David van der Kellen Sr., who continued his tradition of striking historical medals for anniversaries and popular events.

Coin minted for John Adams in 1782 to celebrate recognition of the United States as an independent nation by the Netherlands .
Prize medal awarded in 1784 by Teylers First Society to William Laurence Brown. The design was made in 1778 and Holtzhey stamped the medals for all winners. After his death, the press was bought by the Teylers Stichting and Teylers still stamps the prize medals in the same way.
Prize medal awarded in 1846 by Teylers Second Society to Pieter Otto van der Chijs in 1846.
Commemorative print to celebrate the founding of the Dutch Society of Science in 1752, featuring the prize medal Holtzhey designed for them; engraving by Simon Fokke