Few tourists know that within Rome's medieval churches lie some of the most beautiful Byzantine mosaics in Italy. Many decorate the apses of the city's important churches, including Santa Maria Maggiore, Santa Maria in Trastevere and San Clemente. The oldest mosaics date from the 4th century, when the Roman art of mosaic-making was evolving into early-Christian and Byzantine styles. Those depicting Santa Costanza retain some Roman characteristics: a white background, geometric composition and ornamental motifs. During the reign of Constantine, who decriminalised the Christian religion, many churches were built and ornamental mosaic became the main form of decoration. Often used to cover vast wall areas inside new churches, they were a form of architectural tapestry that, with their uneven tesserae of coloured glass and gold, brilliantly reflected light to create strong effects and sharp colour contrasts.
Rome's early-Christian mosaics also illustrate the progression from the naturalism of Roman art to the symbolism of Christian art, often reflected in the various representations of Jesus Christ. A mosaic in a mausoleum under St Peter's Basilica shows Christ in the form of Apollo. In Chiesa di Santa Pudenziana (390 AD) he is enthroned between the apostles (who are dressed as Roman senators) and his magisterial air is reminiscent of Jupiter. By the 9th century, in Santa Prassede, he has become the Lamb with his faithful flock.The mosaics of Rome's medieval churches are a fascinating and often overlooked treasure for those who cannot spare time to visit Ravenna or Monreale. The following suggested itinerary covers some of the lesser-known churches.
The mid-4th-century Mausoleo di Santa Costanza was built by Constantia, daughter of Constantine, as a mausoleum for herself and her sister Helen. This round church is in the same grounds as the Basilica di Sant'Agnese Fuori-le-Mura, Via Nomentana, a few kilometres north of the centre (catch bus No 62 from Piazza Venezia). As well as the fascinating paleo-Christian mosaics on the barrel-vaulting of the ambulatory , the 7th-century mosaic of St Agnes and Popes symmachus and Honorius I in the apse of the basilica are also worth a look.According to tradition, Santa Pudenziana, one of the oldest churches in Rome, was founded on the site of a house where St Peter was given hospitality. The structure actually incorporated the internal thermal hall of the house. The mosaic in the apse dates from 390 AD and is the earliest of its kind in Rome but, unfortunately, was partially destroyed by a 16th century restoration. The church is in Via Urbana.
Santi Cosma e Damioano, Via del Fori Imperiali, harbours magnificent 6th-century mosaics on the triumphal arch (Christ as the Lamb enthroned, surrounded by candlesticks and angels, as well as the symbols of the evangelists) and mosaics in the apse feature Cosma and Damian being presented to Christ by Peter and Paul and, underneath, Christ as the Lamb, with the 12 apostles also represented as lambs. Bethlehem and Jerusalem are portrayed on either side. The 9th-century Chiesa di Santa Prassede, Via Santa Prassede, was founded in honour of St Praxedes, by Pope Paschal I, who transferred the bones of 2000 martyrs there from the catacombs. The rich mosaics of the apse date from the 9th century and feature Christ in the centre of the semi-dome, surrounded by St Peter, St Pudentiana and St Zeno (to the right) and St Paul, St Praxedes and St Paschal (to the left). Below is Christ as the Lamb and his flock.
The Cappella di San Zenone, inside the church, is the most important Byzantine monument in Rome, built by Paschal I as a mausoleum for his mother. Known as the Garden of Paradise, the chapel has a vaulted interior covered in mosaics, including Madonna with Saints, Christ with Saints and, in the vault, Christ with Angels. The chapel pavement is an early example of opus sectile (polychrome marble), and in a small niche on the right are fragments of a column brought from Jerusalem in 1223. It's said to be the one at which Christ was scourged.
Across the Tiber is the Basilica di Santa Cecilia in Trastevere, Piazza del Mercanti, built in the 9th century by Paschal I over the house of St Cecilia, where she was martyred in 230 AD. The impressive mosaic in the apse was executed in 870 AD and features Christ giving a blessing. To his right are St Peter, St Valerian (St Cecilia's husband) and St Cecilia herself. To his left are St Paul, St Agatha and St Paschal. The holy cities are depicted underneath.