San Giovanni a Porta Latina (Italian: 'Saint John Before the Latin Gate') is a Basilica church near the Aurelian Wall. According to Tertullian, in year 92, St John the Evangelist survived martyrdom at Rome under the Emperor Domitian by being immersed in a vat of boiling oil, from which he emerged unharmed. He was later exiled to island of Patmos. This event was traditionally said to have occurred at the Latin Gate (located on the southern portion of the Roman wall). The nearby chapel of San Giovanni in Oleo is said to be on this very spot. The event was referred to in the Roman Martyrology, which was begun in the seventh century, when already there was a celebration of the event.
The tradition for the building of the Basilica of St. John at the Latin Gate places its construction during the pontificate of Pope Gelasius I (492-496). This is consistent with the oldest of the roof tiles, which have the imprint of a taxation stamp for the Ostrogoth King and ruler of Italy Theodoric the Great (reigned 493-526). One of these ancient roof tiles is now used in the Basilica as a lectern.
In the 8th century, the Basilica was restored by Pope Adrian I, and later the bell-tower and portico were added, and at the end of the 12th century the Basilica was reconsecrated by Pope Celestine III. In the 16th and 17th centuries, a Baroque ceiling and other Baroque features were added to the interior. In the years 1940-1941, the Baroque features were removed and the Basilica was returned to a more primitive simplicity. This last renovation was carried out by the Rosminian Fathers, who, in 1938, were given care of the Basilica and the nearby building, where they opened the Collegio Missionario Antonio Rosmini which houses their International House of Studies.
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.