Fiorino d'oro and the Decameron
There is a short story in the Decameron with interesting references to coins. It is the 3rd "novel" of day six, about a lady called Monna Nonna de' Pulci.
While Messer Antonio d'Orso, a prelate both worthy and wise, was Bishop of Florence, there came thither a Catalan gentleman, Messer Dego della Ratta by name, being King Ruberto's marshal. Now Dego being very goodly of person, and inordinately fond of women, it so befell that of the ladies of Florence she that he regarded with especial favour was the very beautiful niece of a brother of the said bishop. And having learned that her husband, though of good family, was but a caitiff, and avaricious in the last degree, he struck a bargain with him that he should lie one night with the lady for five hundred florins of gold: whereupon he had the same number of popolinos of silver, which were then current, gilded, and having lain with the lady, albeit against her will, gave them to her husband. Which coming to be generally known, the caitiff husband was left with the loss and the laugh against him; and the bishop, like a wise man, feigned to know nought of the affair.
(translation by J.M. Rigg)
Later the bishop and his friend, the marshall are riding to a horse race in the town, and they meet the lady Monna Nonna de'Pulci. The bishop asks her in jest if she would be seduced by the marshall, for which she replies that not likely, but if so, she might want good money.
The fiorino d'oro, was minted from 1252 to 1533 in Florence, so it preceded the Venetian ducat. The obverse of these coins bore the image of St. John, and the inscription S.IOHANNES.B, the reverse displayed a lily and the legend FLORENTIA:
Regarding the question how much Venice copied the fiorino d'oro, the article in the Encyclopaedia Britannica about gold coins states that the ducat and the florin were of the same weight, that is, 54 grains (3.5 grams):
"Florence issued the first of its famous and profuse series of fiorini d'oro, or gold florins. The lily continued as the civic type, together with the standing figure of the Baptist. Regular weight (about 3.50 grams, 54 grains) and fineness won the fiorino universal fame and wide imitation; double florins were introduced in 1504. Venice in 1284 produced its gold ducat, or zecchino (sequin), of the same weight."
The popolino was a silver coin of Milan, of much less value. Here is an image of it:
It indeed has the same design as the fiorino: St. John and the lily, and even the legend is the same. So the story is absolutely plausible. And even if the husband recognized the fake coins, he dared not protest, because he could have been challenged to a duel. As the 'marshall' was a man of military training, he had little chances against him. The Decameron, although calls the husband a 'caitiff', blames rather the bishop who did not defend his relative.
