1 Quattrino - Gregory XIII Jubilee

Gregory XIII proclaimed 1575 a Holy Year, drawing an estimated 300,000 pilgrims to Rome — an extraordinary logistical strain that required emergency coinage production to meet demand for small transactions. The quattrino was the workhorse denomination for this traffic, changing hands at food stalls, hostels, and the alms boxes lining the pilgrimage routes between the four major basilicas.

Billon of this period was notoriously inconsistent in silver content, and Jubilee-year output from the papal mint prioritized volume over alloy discipline.