 The then Special Commissioner for the Province of Umbria of the Kingdom of Sardinia, Gioacchino Napoleone Pepoli, created by decree the Province of Umbriaon 15 December 1860, merging the previous Districts of Perugia, Spoleto, Orvieto, Foligno, Terni and the one of Rieti; therefore Poggio Mirteto, which was in the Rieti District, was included in this new Province.Since 27 January 1927, Poggio Mirteto has been part of the Province of Rieti which was established in the same year by Decree.During World War II, Poggio Mirteto has been theatre of some episodes of the fight against the German occupation by the Partisans.