The Catacomb of Priscilla on the Via Salaria was used for Christian burials from the late 2nd century through the 4th century. This catacomb, according to tradition, is named after the wife of the Consul Manius Acilius Glabrio; he is said to have become a Christian and was killed on the orders of Domitian. Some of the walls and ceilings display fine decorations illustrating Biblical scenes.
The modern entrance to the catacomb is on the Via Salaria through the cloister of the monastery of the Benedictines of Priscilla. The Catacombs of Priscilla are divided into three principal areas: an arenarium, a cryptoportico from a large Roman villa, and the underground burial area of the ancient Roman family, the Acilius Glabrio.
The wall paintings in this catacomb include images of saints and early Christian symbols, such as the painting reproduced in Giovanni Gaetano Bottari's folio of 1754, where the Good Shepherd is depicted as feeding the lambs, with a crowing cock on His right and left hand.
Particularly notable is the 'Greek Chapel' (Capella Greca), a square chamber with an arch which contains 3rd century frescoes generally interpreted to be Old and New Testament scenes, including the Fractio Panis.
The Priscilla catacombs may contain the oldest known Marian paintings, from the early third century. Mary is shown with Jesus on her lap, and the catacombs may have a depiction of the Annunciation, though the latter has been disputed.
On account of the fact that seven early popes and many martyrs were buried in the cemetery, it was known as the 'Queen of the Catacombs' in antiquity. Two popes were buried in the Catacomb of Priscilla: Pope Marcellinus (296 - 304) and Pope Marcellus I (308 - 309).
Alleged relics of Popes Sylvester I, Stephen I, and Dionysius were exhumed and enshrined beneath the high altar of San Martino ai Monti, in the Esquiline area of Rome. Pope Sylvester I was likely originally buried in San Martino ai Monti, although some sources say his remains were transferred there. An unidentified papal sarcophagus discovered during the demolition of Old Saint Peter's Basilica was attributed to Sylvester I and moved to Nonantola Abbey, near the altar that contains the remains of Pope Adrian III. Other sources describe a combination of Sylvester I and Vigilius in an altar in St. Peter's.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.