The tiny Chapel of St Zeno (Cappella di San Zenone), in the church of Santa Prassede, was built by Pope Paschal I (r. 817-24) as a mausoleum for his mother, Theodora. The chapel, with its beautiful mosaics, came to be known as the Orto del Paradiso (Garden of Paradise).
There is a large mosaic above the entrance to the chapel. At the apex of the golden horseshoe is a tondo of the Virgin Mary, who is flanked by two figures, one of whom may be St Zeno. The identities of the eight females figures is also unknown. At the apex of the blue arch is a tondo of Christ. The smaller tondoes depict eleven apostles and St Paul (St Paul and St Peter flank the head of Christ). The two tondoes in the upper corners are thought to be Moses and Elijah.
On the inside wall of the chapel is a depiction of the Etimasia (the preparation for the Second Coming). St Peter and St Paul stand on either side of an empty throne, which is adorned with a gold cross.
The vault is decorated with an image of Christ Pantokrator held up by four angels.
Moving clockwise round the chapel, the second wall portrays three female saints, Agnes, Pudentiana and Praxedes. All three are bearing crowns in their veiled hands. The niche at the bottom is divided into two sections. In the upper part we see the Agnus Dei astride a mound from which flow the four rivers of paradise. Four deer are quenching their thirst from the water. In the lower part we see images of Theodora, the Virgin Mary, St Praxedes and St Pudentiana. Theodora is identified as ‘EPISCOPA’, the word for a female bishop, which has led to all manner of speculation. She has a square halo to indicate that she was alive when the image was made.
On the inside of the arch is a rare depiction of the Anastasis (the Harrowing of Hell), an apocryphal event in which Christ, following his resurrection, breaks down the gates of Hell to release Adam and Eve and other major figures from the Old Testament.
At the top of the back wall is a depiction of the Deisis (a prayer or supplication), in which the Virgin Mary and St John the Baptist act as intercessors for humanity, while Christ as judge is symbolised by the light which enters through the window.
The small apse is decorated with a mosaic from a later period, perhaps the 13th century. The Virgin and Child are flanked by the two sister saints, Praxedes and Pudentiana.
On the fourth wall St John the Evangelist holds his gospel, while St Andrew and St James hold scrolls. All three have their hands covered. In the lunette at the bottom, Christ is giving a blessing to two figures, one of whom may be St Zeno, given the chapel’s dedication.