The Papal States were territories in central Italy that were directly governed by the papacy -- not only spiritually, but in a temporal, secular sense. The extent of papal control, which officially began in 756 and lasted until 1870, varied over the centuries, as did the geographical boundaries of the region. Generally, the territories included present day Lazio (Latium), Marche, Umbria, and part of Emilia-Romagna.
The Papal States were also known as the Republic of Saint Peter, Church States, and Pontifical States; in Italian, Stati Pontifici or Stati della Chiesa.
Origins of the Papal States
The bishops of Rome first acquired lands around the city in the 4th century; these lands were known as the Patrimony of St. Peter. Beginning in the 5th century, when the Western Empire officially came to an end and the influence of the Eastern (Byzantine) Empire in Italy weakened, the power of the bishops, who were now often called "papa" or pope, increased as the populace turned to them for aid and protection. Pope Gregory the Great, for example, did a great deal to help refugees from invading Lombards and even managed to establish peace with the invaders for a time. Gregory is credited with consolidating the papal holdings into a unified territory. While officially the lands that would become the Papal States were considered part of the Eastern Roman Empire, for the most part they were overseen by officers of the Church.
The official beginning of the Papal States came in the 8th century. Thanks to the Eastern empire's increased taxation and inability to protect Italy, and, more especially, the emperor's views on iconoclasm, Pope Gregory II broke with the empire, and his successor, Pope Gregory III, upheld the opposition to the iconoclasts. Then, when the Lombards had seized Ravenna and were on the verge of conquering Rome, Pope Stephen II (or III) turned to the King of the Franks, Pippin III (the "Short"). Pippin promised to restore the captured lands to the pope; he then succeeded in defeating the Lombard leader, Aistulf, and made him return the lands the Lombards had captured to the papacy, ignoring all Byzantine claims to the territory.
Pippin's promise and the document that recorded it in 756 are known as the Donation of Pippin, and provide the legal foundation for the Papal States. This is supplemented by the Treaty of Pavia, in which Aistulf officially ceded conquered lands to the bishops of Rome. Scholars theorize that the forged Donation of Constantine was created by an unknown cleric around about this time, as well. Legitimate donations and decrees by Charlemagne, his son Louis the Pious and his grandson Lothar I confirmed the original foundation and added to the territory.
The Papal States through the Middle Ages
Throughout the volatile political situation in Europe over the next few centuries, the popes managed to maintain control over the Papal States. When the Carolingian Empire broke up in the 9th century, the papacy fell under the control of the Roman nobility. This was a dark time for the Catholic Church, for some of the popes were far from saintly; but the Papal States remained strong because preserving them was a priority of the secular leaders of Rome. In the 12th century, commune governments began to rise in Italy; although the popes did not oppose them in principle, those that were established in papal territory proved problematic, and strife even led to revolts in the 1150s. Yet the Republic of Saint Peter continued to expand. For example, Pope Innocent III capitalized on conflict within the Holy Roman Empire to press his claims, and the emperor recognized the Church's right to Spoleto.
The fourteenth century brought serious challenges. During the Avignon Papacy, papal claims to Italian territory were weakened by the fact that the popes no longer actually lived in Italy. Things grew even worse during the Great Schism, when rival popes tried to run things from both Avignon and Rome. Ultimately, the schism was ended, and the popes concentrated on rebuilding their dominance over the Papal States. In the fifteenth century they saw considerable success, once again due to the focus on temporal over spiritual power displayed by such popes as Sixtus IV. In the early sixteenth century, the Papal States saw their greatest extent and prestige, thanks to the warrior-pope Julius II.
The Decline of the Papal States
But it wasn't long after the death of Julius that the Reformation signalled the beginning of the end of the Papal States. The very fact that the spiritual head of the Church should have so much temporal power was one of the many aspects of the Catholic Church that reformers, who were in the process of becoming Protestants, objected to. As secular powers grew stronger they were able to chip away at papal territory. The French Revolution and the Napoleonic Wars also did damage to the Republic of Saint Peter. Eventually, during the course of Italian unification in the 19th century, the Papal States were annexed to Italy.
Beginning in 1870, when the annexation of the papal territory put an official end to the Papal States, the popes were in a temporal limbo. This came to an end with the Lateran Treaty of 1929, which set up Vatican City as an independent state.