From Italian monte di pietà attested in the sense of "charitable institution that lends money free of charge or at low rates, against a pledge of little value" since the 15th century. Monte designated an autonomous institution that managed the public debt of a municipality or a state (already in 1348-63, Monte Villani), then a public establishment exercising banking functions (1470).

In the Middle Ages the word indicated institutes or places of collection of money (e.g., Monte delle doti in Florence was a public fund established by the government of the Republic of Florence in 1425, its purpose was to provide suitable dowries to Florentine brides, Monte dei maritaggi in Naples), or funds of money put together by several people for various purposes (Monte dell’utilità in Venice).
Monte di pietà, an institute established around 1450, which in 1935 assumed the name of monte di pegni, then changed in 1938 to that of monte di credito su pegno, whose fundamental activity consists in granting loans of even a minimum amount under mild conditions, with guarantee of pledge on movable things; monte (montino in Rome) 'pawn shop': portare l’orologio al monte per impegnarlo 'bring the clock to the pawnshop to pawn it'. As a pawnshop was also established, in 1472, the credit institution that later assumed the name Monte dei Paschi di Siena.

From French mont-de-piété

Clipping from monte de piedad.