Purportedly issued by the fourth century Roman Emperor Constantine I, the Donation grants Pope Sylvester I and his successors, as inheritors of St. Peter, dominion over lands in Judea, Greece, Asia, Thrace, Africa, as well as the city of Rome, with Italy and the entire Western Roman Empire, while Constantine would retain imperial authority in the Eastern Roman Empire from his new imperial capital of Constantinople. The text claims that the Donation was Constantine's gift to Sylvester for instructing him in the Christian faith, baptizing him and miraculously curing him of leprosy.
It has been suggested that an early draft was made shortly after the middle of the eighth century in order to assist Pope Stephen II in his negotiations with Pepin the Short, the Frankish Mayor of the Palace. In 754, Pope Stephen II crossed the Alps to anoint Pepin king, thereby enabling the Carolingian family to supplant the old Merovingian royal line. In return for Stephen's support, Pepin apparently gave the Pope the lands in Italy which the Lombards had taken from the Byzantine Empire. These lands would become the Papal States and would be the basis of the Papacy's secular power for the next eleven centuries.
Inserted among the twelfth-century compilation known as the Decretum Gratiani, this document continued to be used by medieval popes to bolster their territorial and secular power in Italy. It was widely accepted as authentic, although the Emperor Otto III did raise suspicions of the document "in letters of gold" as a forgery, in making a gift to the See of Rome. The poet Dante Alighieri lamented it as the root of papal worldliness in his Divine Comedy. It was not until the mid 15th-century, with the revival of Classical scholarship and textual criticism, the Church had begun to realize that the document could not possibly be genuine.
As early as the fifteenth century its falsity was known and demonstrated. Cardinal Nicholas of Cusa spoke of it as an apocryphal work. Later the Catholic priest Lorenzo Valla in De falso credita et ementita Constantini donatione declamatio (1440, ed. Mainz, 1518), proved the forgery with certainty. Independently of both, Reginald Pecocke, Bishop of Chichester (1450-57), reached a similar conclusion. Among the indications that the Donation must be a fake are its language, and that while certain imperial-era formulas are used in the text, some of the Latin in the document could not have been written in the fourth century; anachronistic terms such as "fief" were used. Also, the purported date of the document is inconsistent with the content of the document itself as it refers both to the fourth consulate of Constantine (315) as well as the consulate of Gallicanus (317).
Pope Pius II wrote a tract in 1453 to show that though the Donation was a forgery, the Church owed its lands to Charlemagne and its powers of the keys to Peter; he did not publish it however, the Vatican essentially ignored Valla: however, though the bulls of Nicholas V and his successors made no further mention of the Donation even when partitioning the New World, Valla's treatise was placed on the list of banned books in the mid-sixteenth century. The Donatio continued to be tacitly accepted as authentic until Caesar Baronius in his "Annales Ecclesiastici" (published 1588-1607) admitted that the Donatio was a forgery, and eventually the church conceded its illegitimacy It has been suggested that this acceptance was hastened by Andeas Helwig's Antichristus Romanus (1612) which had identified the title Vicarius Filii Dei used in the Donation as being the number of the beast. Nearly a century after Baronius, Christian Wolff still alludes to the Donatio as undisputed fact.
More recently, scholars have further demonstrated that other elements, such as Sylvester's curing of Constantine, are legends which originated at a later time. Its recent editor has affirmed that at the time of the composition of Valla's work, Constantine's alleged "donation" was no longer a matter of contemporary relevance in political theory and that, rather, it furnished the theme for a brilliant exercise in legal rhetoric.
Contemporary opponents of papal powers in the Peninsula emphasized the primacy of civil law and civil jurisdiction, now firmly embodied once again in the Justinian Corpus Juris Civilis. The Florentine chronicler Giovanni Cavalcanti reported that, in the very year of Valla's treatise, Filippo Maria Visconti, Duke of Milan, made diplomatic overtures toward Cosimo de' Medici in Florence proposing an alliance in common defence against the Pope, as sovereign lord of the Marche, where Francesco Sforza was currently protected by papal sovereignty, in which Visconti used the words, "It so happens that even if Constantine consigned to Sylvester so many and such rich gifts— which is doubtful, because such a privilege can nowhere be found— he could only have granted them for his lifetime: the Empire takes precedence over any lordship."
Civil law was the Emperor's prerogative, according to the Imperial vassal Visconti: "and for this reason you see why the Church is without civil law. Valla's refutation was taken up vehemently by scholars of the Protestant Reformation, such as Ulrich von Hutten and Martin Luther.
For a detailed account of textual forgery in the early Christian Church, see: