Donation of Constantine

Lorenzo Valla circulates his attack on the Donation of Constantine

One word helped give the forger away: 'satrap' was not the vocabulary Valla expected to find in a fourth-century Roman imperial decree.

Spring 1440, in manuscript

In spring 1440 Lorenzo Valla circulated the first redaction of De falso credita et ementita Constantini donatione, a polemical and philological argument that the supposed imperial donation was forged.

He was not the first to doubt it. Earlier medieval writers and Nicholas of Cusa had challenged the document; what Valla produced was the sustained philological refutation that became famous.

Nothing was printed in 1440. The first printed edition identified by the treatise's modern editor appeared in 1517, edited by Ulrich von Hutten.

Written for a king in a fight with a pope

Valla wrote while serving Alfonso V of Aragon, whose claim to Naples was opposed by Pope Eugenius IV. The treatise attacked the pope's asserted right to treat Naples as a papal fief and award its investiture.

He opened by acknowledging that he was attacking a pope armed with both political power and excommunication — and went on anyway, under a king's protection.

The tests he applied to the text

Valla combined historical, legal and linguistic criticism: that Constantine could not or would not have transferred the western empire, that no ancient history recorded such a transfer, and that the document was full of contradictions, barbarisms and anachronisms.

Among the concrete tests, he challenged the decree's use of Roman 'satraps' and its impossible dating formula, which named Constantine and Gallicanus as fourth-time consuls.

What he demonstrated was that the text is not a fourth-century imperial act. Dating the forgery to the middle or later eighth century is a conclusion of later scholarship, not one Valla securely established.

Sources

Researched 23 Aug 2026 6 sources not yet audited

How this was checked

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What the sources leave uncertain

The composition year 1440 is well supported, and Treccani places circulation of the first redaction in spring 1440, but no single completion or publication day is established.
Some literature describes the work as written in 1439–1440. The strongest biographical source consulted dates the circulated first redaction to spring 1440.
Valla demonstrated that the document was not a fourth-century imperial act. The more specific dating of the forgery to the middle or later eighth century is a conclusion of later scholarship, not a date Valla securely established.