Along the Via Appia, in a natural depression in the ground that housed a pagan necropolis, a Christian cemetery developed from the mid-third century AD. From 258 AD, as witnessed by the creation of a courtyard and a sacred shrine, liturgies were held in honour of the apostles Peter and Paul; the invocations of the faithful scratched on the walls can still be seen. At the remembrance of Peter and Paul, at slightly later time, the burial of the body of St. Sebastian, martyred during the persecutions of the third century, is recalled. Above the place of worship, Constantine (306-337) built a basilica dedicated to the Apostles, which later became the Basilica of San Sebastiano fuori le mura.