Although of ancient foundation, the church of Santa Maria in Trastevere was built at the behest of Pope Innocent II (r. 1130-43). The beautiful mosaics on its façade also date back to this period. What the mosaics exactly represent has never been satisfactorily explained. The Madonna and Child (and two tiny kneeling figures, who are, no doubt, the donors) are flanked by ten young women, eight of whom are crowned and carrying lamps. However, two of the women have no crowns and their lamps are unlit.
The church is entered through a portico (1702), the work of Carlo Fontana.The walls of the portico are covered with fragments of antique and medieval inscriptions. There are also two very faded frescoes of the Annunciation, both of which, unusually, depict the Virgin on the left of the scene. If you look very carefully at the fresco on the south wall, you will see a rare example of the Incarnation of Christ taking the form of a small, naked figure holding a cross.
The main door to the church bears an inscription from Psalm 118: HAEC EST PORTA DOMINI IVSTI INTRABVNT IN EAM (This gate of the Lord, into which the righteous shall enter, KJV). It is surmounted by the Greek letters MHΘY (Meter Theou, Mother of God). Mary was declared to be the mother of God at the Council of Ephesus (431) and Santa Maria in Trastevere claims to be the oldest Marian church in Rome. The nave is divided from the aisles by 21 antique granite columns of varying lengths and thicknesses, which were clearly salvaged from several different buildings. The columns sport both Ionic and Corinthian capitals, some of which are carved with the heads of pagan deities. The columns also support architraves rather than arches and this creates a powerful horizontal accent, which draws the eye to the apse. The triumphal arch sits on two great porphyry columns, which sport finely carved classical capitals. The frescoes on the triumphal arch are from the 19th century.
The beautiful gilded stone ambry, which can be found at the beginning of the nave (to the right), is thought to be the work of the Neapolitan sculptor, Mino del Reame, who was active in Rome between 1460 and 1480). An ambry is used for the storage of the oils used in the sacraments.
The gilded, wooden ceiling was designed by Domenichino (1581-1641), who also painted the Assumption of the Virgin Mary (1617), which we see in the centre. Some scholars think that the complex design of the ceiling was inspired by the Aldobrandini coat of arms, since a cardinal belonging to this family funded its creation.
The Cosmatesque floor was re-laid in the 19th century.
The mosaics on the arch and half-dome of the apse are the glories of the church and date back to the time of Pope Innocent II (1130-43). The spandrels depict the prophets Isaiah and Jeremiah, who are surmounted by the symbols of the four Evangelists. In the centre is an image of the cross from which are suspended the Greek letters alpha and omega (the beginning and the end). If you look closely, you will see two caged birds (under St Mathew and St John), which, some scholars believe, represent Christ imprisoned by the sins of man.
In the apse, above a frieze of the Mystic Lamb/Christ and the twelve sheep/apostles, is the Triumph of the Virgin Mary. Christ is seated on the same throne as his mother, whom he embraces with his right arm. The two figures are flanked by saints and popes, including Innocent II, who holds a model of the church.
The scenes of the Life of the Virgin on the lower register are the work (c. 1298) of Pietro Cavallini, a Roman painter and mosaic designer. The mosaics are generally hailed as marking a major move away from the Byzantine style towards a more naturalistic form of representation.
The mosaic above the episcopal throne is also by Cavallini and depicts the Madonna and Child flanked by St Paul, St Peter and the donor, Cardinal Bertoldo Stefaneschi.
In front of the altar, to the right, a spot marked Fons Olei indicates the place where, according to one legend, a spring of oil suddenly began to flow in 38 or 37 BCE. This was later interpreted by the Christian community as a sign from God announcing the advent of his son. According to another legend, the oil actually sprang up on the year of Christ’s nativity.
At the end of the left aisle is the tomb of Cardinal Philippe d’Alencon, who died in 1397, the work of Giovanni d’Ambrogio. The tomb boasts a beautiful bas-relief of the Death of the Virgin Mary.
In the sacristy, which leads off the left aisle, can be found two treasures, which are often overlooked. They take the form of two tiny ancient Roman mosaics (1st century CE) from Palestrina; one depicts birds, while the other depicts a seaside scene with boats and dolphins.
The aisle ends with the Altemps Chapel, which was designed by Martino Longhi the Elder (1534-91) to commemorate the conclusion of the Council of Trent (1545-63). The fresco on the left wall, which is by Pasquale Cati, has an interesting illustration of the council in session. The chapel houses the Madonna of Mercy, an ancient icon from the 6th or 7th century, which was originally venerated in a street in Trastevere.
The fifth chapel in the left aisle is the Cappella Avila, which was designed by Antonio Gherardi at the end of the 17th century. The chapel’s dome is a gem of Baroque architecture. In the centre of the cupola, we see four angels holding up a small temple or tempietto, which pierces the oculus. The Cappella Bussi, the first chapel on the right, is dedicated to Santa Francesca Roma, and served as the funerary chapel of the Bussi family, to which she belonged. On the left wall is a memorial to Cardinal Giovanni Battista Bussi (1726) and on the right one to Cardinal Pietro Francesco Bussi (1765). Both were designed by Francesco Ferrari. The Bussi family's rather creepy coat of arms comprises nothing more than a pair of eyes! At the end of the right aisle is the Cappella del Coro d'Inverno (Chaple of the Winter Choir) , so called because this is where the Divine Office was sung during the winter months when the main body of the church was too cold, especially in the early morning. In 1759 the chapel was restored by Henry Stuart, Duke of York, on the occasion of his being elected a cardinal. Upon the death of his brother, ‘Bonnie’ Prince Charlie, in 1788, the cardinal came to be known by the Jacobites as King Henry IX of England and Ireland and King Henry I of Scotland. This explains the presence of the royal coat of arms above the entrance.