An altar frontal was originally a piece of embroidered needlework, cloth of gold, or tapestry, placed before the altar, usually as wide as the altar itself but sometimes even extended along the two sides of it. Its purpose was to decorate the altar while separating it from the rest of the church, and to attract the eyes of the believers attending the Mass.
In the 11th century, the structure was usually made of metal, in the 13th century of stone, and from the 14th century of wood.
The altar frontal (dating to the 13th century) is made of stone and shows Jesus Christ in the central mandorla sitting on His throne while blessing, surrounded by the emblems of the four Evangelists (the lion – Saint Mark; the eagle – Saint John; the angel – Saint Matthew; the ox – Saint Luke). On each side of the central mandorla, four figures stand on two lines.
The female one wearing a veil, by Christ’s right side, can be identified as the Virgin Mary, while the male figure just next to her could be “the disciple whom Jesus loved”, perhaps John himself (Gospel according to Saint John, 19, 26-27: When Jesus saw his mother there, and the disciple whom he loved standing nearby, he said to her, “Woman, here is your son,” and to the disciple, “Here is your mother.” From that time on, this disciple took her into his home). Beneath them stands Saint Peter, holding the key of Heaven and next to him probably Saint Paul (according to Saint Augustine, bishop of Hippo, they were martyred on the same day, June 29, in different years so they share the same feast day).
We are not able to identify the four saints on Jesus’ left side. The panel used to be painted, as revealed by the many traces of pigments, still detectable. The other stone relics in the room are the remains of a church’s furnishing. One bears the decoration of a lion. The other one was probably reused in the Middle Ages as a part of a pulpit (the raised platform from which the preacher delivered the sermon during the Mass) but was originally a Roman funerary stone slab: in fact, if you turn it over you will discover some traces of Roman capital letters.
The upper stone slab shows stylistic differences compared to the lower one. In the first one, the figures, characterized by greater naturalism, are set under round arches, in the second slab they are under trefoil arches with greater depth. It is probable that two different artists were involved in the execution
The frame of this altar frontal features a decoration with plant motifs and birds
