The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II. Innocent II razed the church along with the recently completed tomb of the Antipope Anacletus II, his former rival. Innocent II arranged for his own burial on the spot formerly occupied by the tomb.
The present nave preserves its original (pre-12th century) basilica plan and stands on the earlier foundations. The 22 granite columns with Ionic and Corinthian capitals that separate the nave from the aisles came from the ruins of the Baths of Caracalla, as did the lintel of the entrance door. Inside the church are a number of late 13th-century mosaics by Pietro Cavallini on the subject of the Life of the Virgin (1291) centering on a 'Coronation of the Virgin' in the apse. Domenichino's octagonal ceiling painting, Assumption of the Virgin (1617) fits in the coffered ceiling setting that he designed.
The Romanesque campanile is from the 12th century. Near the top, a niche protects a mosaic of the Madonna and Child. The mosaics on the façade are believed to be from the 12th century. They depict the Madonna enthroned and suckling the Child, flanked by 10 women holding lamps. This image on the façade showing Mary nursing Jesus is an early example of a popular late-medieval and renaissance type of image of the Virgin. The motif itself originated much earlier, with significant 7th century Coptic examples at Wadi Natrun in Egypt.
References:Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.