Catacombs of SS. Marcellino and Pietro and Mausoleum of S. Elena

In the area of the Mausoleum of Sant'Elena, known as ad duas lauros or inter duas lauros, within the imperial estate, necropolises sprang up from the late Republican age onwards, extending along the Via Labicana, today's Casilina. Between the 2nd and 3rd century AD, this area was occupied by the cemetery of the equites singulares, members of the imperial guard. During the time of Christian persecution, it was also chosen as a place for the graves of some martyrs, who were immediately subjected to veneration. Between 315 and 325 AD, Constantine built a circiform basilica within the fundus, a place near the imperial palace of the Sessorium, occupied by cemeteries of martyrs, the necropolis of the imperial guard, which he himself had disbanded because he had sided with Massenzio, was also demolished. The building was in honour of Santi Marcellino and Pietro, who perished during the Diocletian persecution, with the construction of the dynastic mausoleum of his mother Elena, the emperor began the monumental Christianisation of the Urbe.
The building had a circular ground plan with a diameter of over 20 metres and was preceded, to the west, by a rectangular atrium originally connected to the narthex of the basilica, now only the foundations are preserved. The basement had circular and rectangular niches inside, originally decorated with marble incrustations, while the roof was formed by a mosaic comprising two concentric circles of Iberian oil amphorae. This is where the modern name Tor Pignattara comes from.
The catacombs dedicated to Santi Marcellino e Pietro developed near the basilica, containing a rich collection of paintings, mostly dating back to the 4th century BC, which represent a veritable picture gallery of the period.
The demolition of the building probably took place between the 11th and 12th century, coinciding with the removal of Sant'Elena's body and the conveyor of her porphyry sarcophagus to the Lateran. From then on, imperial property was transferred to the Church of Rome, confirming the transfer of power from the state to ecclesiastical authority. In the 17th century, the small church of Santi Marcellino and Pietro and its rectory were built inside the mausoleum, which was enlarged in the 18th century, when the main niche, where the sarcophagus of St Helena was located, was closed.
By reading the testimonies within their contexts of origin, the exhibition succeeds in realising the musealisation of the area: the finds from the cemetery of the equites singulares and the catacomb below exemplify the progressive Christianisation of the suburbs. The monument has also been restored and is now open to the public, thanks to the collaboration with the Pontifical Commission for Sacred Archaeology, with an itinerary that includes the collection of artefacts found in the excavations.