this may have been one of the many technological innovations that was lost after the collapse of the Roman Empire.
gallienus1, It did not happen exactly like that.
Indeed, in the
Byzantine era occurred an evolution of this technology.
The pic posted by Helen shows a pincer die for a gold
solidus of
Constans I,
Antiochia mint, from the
collection of the Cabinet
des Médailles of the Bibliothèque Nationale in
Paris. (published in
Babelon 1901 coll.897 ss.; and also in:
Vermeule "Some notes in ancient dies and coining methodes".
London 1954, p.35, n,58)
Here another pic of the same object, open
Using this kind of pincer
Romans should strike heavy coins with two minters: one putting dies and flans in place and one striking, and some scholars think that in fact
Romans used three minters, one putting flans in place and two striking by turns.
In the next pic a pincer die used in the VI century for a
solidus of Justinn I, stored in the Fogg Art Museum (
Vermeule "Some notes in ancient dies and coining methodes".
London 1954, p.7):
As you can see this is quite a technological innovation, in fact now the
work can be done by a single minter, putting flans and then striking, holding pincer in one hand and hammer in the other hand.
The theory which claimed that the high Middle Ages were "dark ages" is
obsolete since at least 20 years ago. Modern scholars see that in those centuries there was a continuation of the evolution of civilization, who took other cultural forms, but it never really regressed.
Hope this can be of your interest.
Bye
Nico