Finance

Even the Roman money -although it was issued by a central authority- was backed by gold, silver, bronze and other commodities, at least partially (inflationary debasement of coins became an important feature over the centuries).

But, yes, to a high degree this is hairsplitting, and you may agree that comparing currency systems of different historical epochs doesn't make sense as their economies and societies are too different for such a rough comparison.

What I say is that our current fiat currency system -the one we have since 1971- is unique in that it is largely created by banks themselves: The money volume created by the fractional reserve system is much larger than the volume printed by the central bank (~ ten times). This is unique in history to the best of my knowledge, l don't know of a similar example. And imo it is a huge part of the current financial problems we have been facing for some time, including the problems described in the linked article.