The Donation of Constantine (Latin: Donatio Constantini) is a forged Roman imperial decree by which the 4th-century emperor Constantine the Great supposedly transferred authority over Rome and the western part of the Roman Empire to the Pope. Composed probably in the 8th century, it was used, especially in the 13th century, in support of claims of political authority by the papacy.
Donation of Constantine. Accessed May 7th, 2024. In Wikipedia. https://en.wikipedia.org/wiki/Donation_of_Constantine
Vicarius Filii Dei (Latin: Vicar or Representative of the Son of God) is a phrase first used in the forged medieval Donation of Constantine to refer to Saint Peter, who is regarded as the first Pope by the Catholic Church....
It et cuncto populo Romanae gloriae imperij subiacenti, ut sicut in terris vicarius filii Dei esse videtur constitutus etiam et pontifices
Vicarius Filii Dei. Accessed May 7th, 2024. In Wikipedia. https://en.wikipedia.org/wiki/Vicarius_Filii_Dei
...in the ecclesiastical sense (12c.), from Latin vicarius "a substitute, deputy, proxy," noun use of adjective vicarius "substituted, delegated,"
Vicar. Accessed May 7th, 2024. In Online Etymology Dictionary. https://www.etymonline.com/word/vicar