donation of Constantine

An apocryphal document attributed to Emperor Constantine I and addressed to Pope Silvester. It relates how the pope managed to convert the emperor and allegedly transfer power over Rome, Italy, and the W provinces to the papacy, who used it to justify its political and religious supremacy. Although dated 313, the document dates back to the 8th-c. Its authenticity had already been questioned by Otto I and Nicolò Cusano, and was finally certified as a fake by Lorenzo Valla in 1440.

The Donation of Constantine (Latin, Constitutum Donatio Constantini or Constitutum domini Constantini imperatoris) is a forged Roman imperial edict devised probably between 750 and 850.

Purportedly issued by the fourth century Roman Emperor Constantine I, the Donation grants Pope Sylvester I and his successors, as inheritors of St Peter, the dominion over the city of Rome, 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 reward to Sylvester for instructing him in the Christian faith, baptizing him and miraculously curing him of leprosy.

This document was used by medieval popes to bolster their claims for territorial and secular power in Italy. However, by the mid 15th-century, with the revival of Classical scholarship and textual critique, the Church had begun to realize that the document could not possibly be genuine. The Italian humanist Lorenzo Valla proved in 1440 that the Donation must be a fake by analyzing its language, and showing 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 4th century. Also, the date given in the document does not add up, as it refers both to the fourth consulate of Constantine (315) as well as the consulate of Gallicanus (317).