PIETRO di MALLO (Petrus Mallii or Manlii). — He is known as a presbyter attached to the liturgical offices of the Basilica of St Peter in the Vatican during the second half of the 12th century and as the author of a complete collection of epigraphic, dedicatory, and sepulchral texts then existing in that basilica.
He was prompted to compile this collection because the deacon Giovanni had dedicated to Pope Alessandro III (1159–81) a writing exalting the supremacy of the Lateran Basilica over the other churches; P. opposed it with a writing of his own, likewise dedicating it to Pope Alessandro III, in order in turn to champion the primacy of the Vatican Basilica over the other basilicas and churches of Rome and of the Orbis, since it was founded upon the tomb of the Prince of the Apostles and contained the tombs of the first popes, as well as on account of the artistic merit of its construction and monuments. At certain points the pamphlet advanced its arguments by almost paraphrasing those of its opponent. In describing the Vatican Basilica, the author includes the texts of the epitaphs of the popes buried there and various inscriptions existing in the chapels and other parts of the building, in order further to exalt the importance of the distinguished sacred edifice. The manuscript is preserved in the Vatican Basilica; the text is contained in a codex of the Bibliothèque de Clermont and was edited by Ianning in the Acta Sanctorum (Iunii, VII, pp. 37–54). Cod. Vat. 6757, from the beginning of the 13th century, contains a recension of the text with additions by the Roman presbyter attached to the same basilica; it was edited by Paolo de Angelis in 1646. It was published again by G. B. De Rossi, from cod. Vat. 3627, of the 16th century, which derived from a copy dating from the end of the 12th century.