THEOPHYLACTUS. – A Roman figure who first appears in 90 in a decree of Emperor Louis III in Rome.
He was *vestararius*, i.e., head of the papal administration, but the titles with which he was subsequently invested attest to the progressive increase of his authority. T. was the most prominent figure in the anti-Formosan party, and his political position, considerably strengthened by the accession to the throne of Sergius III (v.), an old friend of his and his family, brought to Rome by Alberic of Spoleto, an adventurer who had seized the Duchy by killing the last duke, was further consolidated by the marriage of his daughter Marozia to Alberic and by the elevation X (v.), which had come about through his efforts. Assisted by Alberic of Spoleto, T. effectively supported John X in the military expedition against the Saracens of the Garigliano and in the negotiations that led to the imperial coronation of Berengar I (v.), from whom they hoped for strong support against internal and external enemies (915). Alberic and T. died at a short interval from one another, shortly before 926, and their Marozia (v.).