MARCUS and MARCELLIANUS, saints, martyrs. — They are commemorated in the Martyrologium Hieronymianum on June 18. On the same date their Mass is found in the Gelasian and Gregorian Sacramentaries. The Itineraries of the 7th century recall them on the Via Ardeatina, lying beneath the altar of an above-ground basilica; the Salisburgensis adds that they were twins and deacons.
It has been claimed that their tomb has been identified, but none of the hypotheses advanced can be considered certain. The few details regarding their martyrdom are provided by that hagiographic romance which is the Passio of St. Sebastian: it can therefore be said that nothing positive is known.
The Martyrologium Hieronymianum places their tombs in the cemetery of Balbina on the Via Ardeatina, while the catalogue of cemeteries places them in a cemetery of Basil on the Via Ardeatina, which is entirely unknown.
In 1903, G. Wilpert believed he could identify the cemetery discovered near the then monastery of the Trappists, now the Istituto S. Tarcisio, on the Via Appia, as the cemetery of Marcus, Marcellianus, and Damasus mentioned in the Liber Pontificalis for the works completed by Pope John VII (705–707); but at that time the term *coemeterium* stood for basilica. The two martyrs are indicated as buried on the Via Ardeatina in the cemetery of Balbina, not yet identified. The pilgrims of the 7th century visited their tomb in an above-ground basilica and not in an underground cubiculum, in which instead O. Marucchi wished to recognize the tomb of the “confessores sanciti quos Graecia misit” that Damasus lists among the group of St. Callistus.
The cemetery discovered in 1903 was partly already known to De Rossi; it consists of an above-ground area and an underground region which inscriptions, sarcophagi, and paintings assign to the 4th century.