Abdon and Sennen are among the first martyrs who came to be venerated by the Roman church. The most ancient information we have regarding the devotion to them comes from the Depositio martyrum of around 336 CE, included in the Chronograph of 354 by Philocalus. On Jul 29 it contains the following notices: III kal. Aug. Abdos et Semnes in Pontiani, quod est ad ursum piliatum (MGH Chronica Minora, vol. I, 1892, 71). The notice of the Depositio was taken up by the Martyrologium Hieronymianum for Jul 30. They were known and venerated, since their names are also found in the Marble Calendar of Naples (…