MARCO, POPE, saint. - He was a Roman by birth and son of Priscus; he governed the Roman Church for about nine months, from 18 January to 7 October 356. Little is known of his deeds; he seems not to have concerned himself at all with the Arian controversy, since the correspondence with St. Athanasius attributed to him by Pseudo-Isidore is certainly spurious.
The Liber Pontificalis attributes to him the granting of the pallium and the prerogative of the bishop of Ostia to consecrate the new bishop of Rome. He built two basilicas: one in the city, the Titulus Marci, brought to light in recently conducted excavations; the other on the Via Ardeatina, now vanished. His burial in the cemetery of Balbina on 7 October is recorded in the Depositio episcoporum; under the same date he is commemorated by the Martyrology and the Roman Breviary.