5 Soldi / 25 Centesimi - Pius IX

This denomination was a direct product of the monetary upheaval following Italian unification. When the Kingdom of Italy adopted the Latin Monetary Union standard in 1865, the Papal States — still an independent sovereignty under French military protection — were forced into a practical alignment with the new decimal system despite having no political incentive to cooperate. The 25 Centesimi denomination was essentially an accommodation to commercial reality along the border territories.

Pius IX had already lost the Romagna, Marche, and Umbria to Piedmont by 1860. These 1866–1867 issues were struck while Rome itself was the last remaining piece of the temporal domain, its survival depending entirely on the French garrison stationed there under the September Convention.