The nucleus of the states consisted of endowments given to the popes from the 4th cent. in and around Rome, in other areas of the Italian mainland, and in Sicily, Sardinia, and other lands; these came to be called the Patrimony of St. Peter. The popes gradually lost their more distant lands, but in the duchy of Rome papal power became stronger and increasingly independent of the Eastern emperors and of the other states in Italy.
In 754 (confirmed 756), Pepin the Short gave to Pope Stephen II the exarchate of Ravenna and the Pentapolis (Rimini, Ancona, Fano, Pesaro, and Senigallia). (Like Pope Zacharias, Pope Stephen II had recognized Pepin as rightful king of the Franks, and Pepin now needed papal assistance against the Lombards.) Over these vast territories the popes were long unable to exercise effective temporal sovereignty. In 774, Charlemagne confirmed the donation of his father, Pepin the Short; moreover, to give the papal claim to temporal power greater antiquity, the so-called Donation of Constantine (see Constantine, Donation of) to Pope Sylvester I was forged. On its basis later popes also claimed suzerainty over Naples, Sicily, and Sardinia. In 1115, Countess Matilda of Tuscany, by leaving her territories to the church, helped to precipitate a long struggle between popes and emperors.
In Rome itself, the popes' temporal power, almost nonexistent in the 10th cent., remained greatly limited until the 14th cent. by the interference of the emperors, by the power of the nobles, and by the ambitions of the commune of Rome, which contended that its authority also extended over the Papal States. In the 13th and 14th cent., the emperors renounced their claims to the duchy of Spoleto, the Romagna, and the March of Ancona; however, the free communes and petty tyrannies that dominated these regions long resisted effective papal control. The Comtat Venaissin, a papal possession in S France until 1791 (though not a part of the Papal States), was acquired in 1274; in 1309, Avignon became the seat of the popes. From 1309 to 1417, during the "Babylonian Captivity" at Avignon and the Great Schism, the Papal States were in chaotic condition, only temporarily relieved by the efforts of Cardinal Albornoz.
Actual control by the papacy of its territories began in the 16th cent., when Cesare Borgia, son of Pope Alexander VI, conquered the petty states of the Romagna and Marche; after his fall (1503) most of them passed directly under papal rule. In the early 16th cent., Pope Julius II consolidated papal power by abolishing local autonomies and by participating effectively in the Italian Wars. The last principalities to lose their autonomy to the popes were Ferrara (1598) and Urbino (1631). The duchy of Castro was added in 1649. Parma and Piacenza were alienated (1545) through the nepotism of Pope Paul III.
After the Counter Reformation (16th cent.) the spiritual power of the papacy grew while its political power waned. Papal troops, mostly Swiss and other mercenaries, offered almost no resistance to the French invaders under Napoleon Bonaparte (see Napoleon I) in 1796. Pius VI and his successor, Pius VII, saw their states curtailed, occupied, and twice abolished between 1796 and 1814. The Congress of Vienna fully restored (1815) the states of the papacy and placed them under Austrian protection.
Conspiracies and revolutions (notably of 1831 and 1848-49) characterized the following decades. Pius IX was liberal at his accession and granted his states a constitution, but the events of 1848 turned him against the revolutionists. During the Risorgimento, only French intervention at Rome prevented the total absorption of the Papal States. After the Austrians left (1859) Bologna and the Romagna, both united (1860) with the kingdom of Sardinia, as did Marche and Umbria. Giuseppe Garibaldi invaded the remaining Papal States twice but was prevented from taking Rome—in 1862 by the intervention of Victor Emmanuel II of Italy, and in 1867 by Napoleon III.
The fall of Napoleon permitted Victor Emmanuel to seize Rome in 1870. However, Pius IX refused to recognize the loss of temporal power and became a "prisoner" in the Vatican; his successors followed his example. The so-called Roman Question was only resolved in 1929 by the Lateran Treaty, which, among other things, established Vatican City.
See L. M. Duchesne, The Beginnings of the Temporal Sovereignty of the Popes, A.D. 754-1073 (1898, tr. 1908); D. P. Waley, The Papal State under Martin V (1958); P. Partner, The Lands of St. Peter: The Papal State in the Middle Ages and the Early Renaissance (1972). See also bibliography under papacy.
The plural Papal States is usually preferred; the singular Papal State (equally correct since it was not a mere personal union) is rather used (normally with lower-case letters) for the modern State of Vatican City, an enclave within Italy's national capital, Rome. Vatican City was founded in 1929, again allowing the Holy See the practical benefits of territorial sovereignty.
The seeds of the Papal States as a sovereign political entity were planted in the sixth century. The Eastern Roman (or Byzantine) government in Constantinople launched a reconquest of Italy that took decades and devastated the country's political and economic structures; just as those wars wound down, the Lombards entered the peninsula from the north and conquered much of the countryside. By the seventh century, Byzantine authority was largely limited to a diagonal band running roughly from Ravenna, where the Emperor's representative, or Exarch, was located, to Rome and south to Naples. With effective Byzantine power weighted at the northeast end of this territory, the Bishop of Rome, as the largest landowner and most prestigious figure in Italy, began by default to take on much of the ruling authority that Byzantines were unable to project to the area around the city of Rome. While the Bishops of Rome — now beginning to be referred to as the Popes — remained de jure Byzantine subjects, in practice the Duchy of Rome, an area roughly equivalent to modern-day Latium, became an independent state ruled by the Church.
The Church's relative independence, combined with popular support for the Papacy in Italy, enabled various Popes to defy the will of the Byzantine emperor; Pope Gregory II even excommunicated emperor Leo III the Isaurian. Nevertheless the Pope and the Exarch still worked together to control the rising power of the Lombards in Italy. As Byzantine power weakened, though, the Papacy took an ever larger role in defending Rome from the Lombards, usually through diplomacy, threats and bribery. In practice, the papal efforts served to focus Lombard aggrandizement on the Exarch and Ravenna. A climactic moment in the founding of the Papal States was the agreement over boundaries embodied in the Lombard king Liutprand's Donation of Sutri (728) to Pope Gregory II
When the Exarchate finally fell to the Lombards in 751, the Duchy of Rome was completely cut off from the Byzantine Empire, of which it was theoretically still a part. Pope Stephen II acted to neutralize the Lombard threat by courting the de facto Frankish ruler, Pepin the Short. With the urging of Pope Zachary to depose the Merovingian figurehead Childeric III, Pepin was crowned in 751 by Saint Boniface. Stephen later granted Pepin the title Patrician of the Romans. Pepin led a Frankish army into Italy in 754 and 756. Pepin defeated the Lombards taking control of northern Italy and made a gift (called the Donation of Pepin) of the properties formerly constituting the Exarchate of Ravenna to the Pope. In 781, Charlemagne codified the regions over which the Pope would be temporal sovereign: the Duchy of Rome was key, but the territory was expanded to include Ravenna, the Pentapolis, parts of the Duchy of Benevento, Tuscany, Corsica, Lombardy and a number of Italian cities. The cooperation between the Papacy and the Carolingian dynasty climaxed in 800, when Pope Leo III crowned Charlemagne the first "Emperor of the Romans" ('Augustus Romanorum').
However, the precise nature of the relationship between the Popes and Emperors — and between the Papal States and the Empire — was not clear. Was the Pope a sovereign ruler of a separate realm in central Italy, or were the Papal States just a part of the Frankish Empire over which the Popes had administrative control? Or, on the other hand, were the Holy Roman Emperors vicars of the Pope (as a sort of Archemperor) ruling Christendom, with the Pope himself, however, being directly responsible only for the environs of Rome and then delegating the rest to the Emperor in order to concentrate on his spiritual duties? Events in the 9th century postponed the conflict: the Frankish Empire collapsed as it was subdivided among Charlemagne's grandchildren, and the papacy's prestige declined, with the tyranny of the local Roman nobility in the tenth century, into the condition later dubbed the pornocracy, or "rule by harlots". In practice, the Popes were unable to exercise effective sovereignty over the extensive and mountainous territories of the Papal States, and the region preserved its old Lombard system of government, with many small countships and marquisates, each centered upon a fortified rocca.
Over several campaigns in the mid-tenth century, the German ruler Otto I conquered northern Italy; Pope John XII crowned him emperor (the first so crowned in more than forty years), and the two of them ratified the Diploma Ottonianum, which guaranteed the independence of the Papal States. Yet over the next two centuries, Popes and Emperors squabbled over a variety of issues, and the German rulers routinely treated the Papal States as part of their realms on those occasions when they projected power into Italy. A major motivation for the Gregorian Reform was to free the administration of the Papal States from imperial interference, and after the extirpation of the Hohenstaufen dynasty, the German emperors rarely interfered in Italian affairs. By 1300, the Papal States, along with the rest of the Italian principalities, were effectively independent.
From 1305 to 1378, the Popes lived in Avignon, in what is now France, and were under the influence of the French kings in what was known as the 'Babylonian Captivity'. During this Avignon Papacy, however, much of the Papal States in Italy remained only formally under Papal control; in fact, 1357 marks a watershed in the legal history of the Papal States, when Cardinal Albornoz promulgated the Constitutiones Sanctæ Matris Ecclesiæ, which replaced the mosaic of local law and accumulated traditional 'liberties' with a uniform code of civil law. The promulgation of the Constitutiones Egidiane followed the military progress of Albornoz and his condottieri heading a small mercenary army. Having received the support of the archbishop of Milan and Giovanni Visconti, he defeated Giovanni di Vico, lord of Viterbo, moving against Galeotto Malatesta of Rimini and the Ordelaffi of Forlì, the Montefeltro of Urbino and the da Polenta of Ravenna, and against the cities of Senigallia and Ancona. The last holdouts against full papal control were Giovanni Manfredi of Faenza and Francesco II Ordelaffi of Forlì. Albornoz, at the point of being recalled in 1357, in a meeting with all the Papal vicars, 29 April 1357, issued the Constitutiones; they remained in effect until 1816.
During this period the city of Avignon itself was added to the Papal States; it remained a papal possession even after the popes returned to Rome, only passing back to France during the French Revolution.
At its greatest extent, in the 18th century, the Papal States included most of Central Italy — Latium, Umbria, Marche and the Legations of Ravenna, Ferrara and Bologna extending north into the Romagna. It also included the small enclaves of Benevento and Pontecorvo in southern Italy and the larger Comtat Venaissin around Avignon in southern France.
The French Revolution proved as disastrous for the temporal territories of the Papacy as it was for the Catholic Church in general. In 1791 the Comtat Venaissin and Avignon were annexed by France. Later, with the French invasion of Italy in 1796, the Legations were seized and became part of the revolutionary Cisalpine Republic. Two years later, the Papal States as a whole were invaded by French forces, who declared a Roman Republic. Pope Pius VI died in exile in France in 1799. The Papal States were restored in June of 1800 and Pope Pius VII returned, but the French again invaded in 1808, and this time the remainder of the States of the Church were annexed to France, forming the départements of Tibre and Trasimène.
With the fall of the Napoleonic system in 1814, the Papal States were restored. From 1814 until the death of Pope Gregory XVI in 1846, the Popes followed a harshly reactionary policy in the Papal States. For instance, the city of Rome maintained the last Jewish ghetto in Western Europe. There were hopes that this would change when Pope Pius IX was elected to succeed Gregory and began to introduce liberal reforms.
In the years that followed, Italian nationalists — both those who wished to unify the country under the Kingdom of Sardinia and its ruling House of Savoy and those who favored a republican solution — saw the Papal States as the chief obstacle to Italian unity. Louis Napoleon, who had now seized control of France as Emperor Napoleon III, tried to play a double game, simultaneously forming an alliance with Sardinia and playing on his famous uncle's nationalist credentials on the one hand and maintaining French troops in Rome to protect the Pope's rights on the other.
After the Second Italian War of Independence, much of northern Italy was unified under the House of Savoy's government; in the aftermath, Garibaldi's expedition of the Thousand overthrew the Bourbon monarchy in the Kingdom of the Two Sicilies. Afraid that Garibaldi would set up a republican government in the south, the Sardinians petitioned Napoleon for permission to send troops through the Papal States to gain control of the Two Sicilies, which was granted on the condition that Rome was left undisturbed. In 1860, with much of the region already in rebellion against Papal rule, Sardinia conquered the eastern two-thirds of the Papal States and cemented its hold on the south. Bologna, Ferrara, Umbria, the Marches, Benevento and Pontecorvo were all formally annexed by November of the same year, and a unified Kingdom of Italy was declared. The Papal States were reduced to the Latium region surrounding Rome, raising the Roman Question.
Rome was declared the capital of Italy in March 1861, when the first Italian Parliament met in the kingdom's old capital Turin in Piedmont. However, the Italian Government could not take possession of its capital, because Napoleon III kept a French garrison in Rome protecting Pope Pius IX. The opportunity to eliminate the last vestige of the Papal States came when the Franco-Prussian War began in July 1870. Emperor Napoleon III had to recall his garrison from Rome for France's own defence and could no longer protect the pope. Following the collapse of the Second French Empire at the battle of Sedan, widespread public demonstrations demanded that the Italian Government take Rome. King Victor Emmanuel II sent Count Ponza di San Martino to Pius IX with a personal letter offering a face-saving proposal that would have allowed the peaceful entry of the Italian Army into Rome, under the guise of offering protection to the pope.
According to Raffaele De Cesare:
This event, described in Italian history books as a liberation, was taken very bitterly by the Pope. The Italian government had offered to allow the Pope to retain control of the Leonine City on the west bank of the Tiber, but Pius rejected the overture. Early the following year, the capital of Italy was moved from Florence to Rome. The Pope, whose previous residence, the Quirinal Palace, had become the royal palace of the Kings of Italy, withdrew in protest into the Vatican, where he lived as a self-proclaimed "prisoner", refusing to leave or to set foot in St. Peter's Square, and forbidding (Non Expedit) Catholics on pain of excommunication to participate in elections in the new Italian state.
However the new Italian control of Rome did not wither, nor did the Catholic world come to the Pope's aid, as Pius IX had expected. In the 1920s, the papacy — then Pius XI — renounced the bulk of the Papal States and signed the Lateran Treaty (or Concordat with Rome) of 1929, which created the State of the Vatican City, forming the sovereign territory of the Holy See (which is also a subject under international law in its own right). Vatican City can be seen as the modern descendent of the Papal States.