The Papal States

When the Western Roman Empire collapsed in the fifth century, it left a political vacuum on the Italian peninsula. The pope, virtually the only figure of significant standing, gradually filled the void, assuming political control over Rome. In 756 this de facto control was made official by the Frankish ruler, Pepin, who had recently defeated a Lombard invasion that threatened Rome.  In exchange for the title of king, Pepin ‘donated’ his newly-conquered lands surrounding the two cities of Rome and Ravenna to the pope.  The resulting Papal States (also called the Republic of Saint Peter) were ruled directly by the popes until the nineteenth century when they were dissolved during the Risorgimento (unification of Italy).  

The exact borders and power of the Papal States fluctuated considerably during the middle ages.  At their greatest extent they covered the modern central Italian regions of Lazio, Umbria, Marche, and part of Emilia-Romagna.  This territory was guarded by the papal armies, which were commanded in the field by mercenaries, or on occasion, by the pope himself.  This period of papal history is best represented by the Renaissance pontiff, Julius II, who built an army around a core of Swiss mercenaries and gained the epithet the Warrior Pope for his frequent military excursions.  

After the unification of Italy in 1871, the pope’s temporal power was restricted to the walls of the Vatican compound, but even that was in doubt.  In 1929, an accommodation was reached with the Italian government, which recognized an independent state of ‘Vatican City’. It is still protected by Julius’ Swiss Guard, a remnant of the time when popes fought temporal - as well as spiritual - wars.