Before the end of the eighth century, some apostolic scribe, perhaps the notorious Isidore, composed the decretals, and the donation of Constantine, the two magic pillars of the spiritual and temporal monarchy of the popes.
This memorable donation was introduced to the world by an epistle of Adrian the First, who exhorts Charlemagne to imitate the liberality, and revive the name, of the great Constantine.

[68] According to the legend, the first of the Christian emperors was healed of the leprosy, and purified in the waters of baptism, by St.Silvester, the Roman bishop; and never was physician more gloriously recompensed.

His royal proselyte withdrew from the seat and patrimony of St.Peter; declared his resolution of founding a new capital in the East; and resigned to the popes the free and perpetual sovereignty of Rome, Italy, and the provinces of the West.

[69] This fiction was productive of the most beneficial effects.

The Greek princes were convicted of the guilt of usurpation; and the revolt of Gregory was the claim of his lawful inheritance.