Libellus de imperatoria potestate in urbe Roma is an anonymous Latin treatise on the authority of the Holy Roman Emperor in the city of Rome.
[a] The Libellus argues for the authority of the Holy Roman Emperor in the so-called "patrimony of Saint Peter".
[3][b] The author clearly sides with the Emperor Louis II against Pope Nicholas I.
[1] Ferdinand Gregorovius calls its author an "Imperialist" and a "partisan", and doubts the accuracy of his claim that "[the emperor's] legate resides in Rome at all times".
[c] According to Eleanor Duckett, the author of the Libellus "poured out his feelings into that interesting document".