The underground basilica church at the Catacombs of Domitilla on the Appian Way, virtually lost in the early Middle Ages and rediscovered in the 1870s by the archaeologist Giovanni Battista de Rossi, carries the same dedication to Nereo and Achilleo.

[1] A 337 epitaph inscription[2] in the Basilica di San Paolo fuori le Mura celebrates the late Cinnamius Opas, lector of a church known as Titulus Fasciolae;[3] the name has traditionally been explained as the place where St. Peter lost the foot bandage (fasciola) that wrapped the wounds caused by his chains, on his way to escape the Mamertine Prison.

The original columns were replaced in the 15th century by octagonal pillars, and the nave is characterized by the large fresco decorations commissioned by Cardinal Baronio.

In the apse behind the altar is the episcopal throne assembled under the direction of the antiquary Cardinal Baronius, reusing lions, in the Cosmatesque style that is associated with the Vassalletto school,[8] which support the armrests; on the backrest is inscribed the opening and closing words of the twenty-eighth homily of St. Gregory the Great, inscribed under the mistaken tradition that he preached them here, in front of the relics of Sts.

When Cardinal Baronio ordered the inscription,[9] he did not know that the relics were originally buried in the underground basilica of the Catacomb of Domitilla, so thought that this was the place St Gregory preached.