The presbytery is a square space, separated from the nave, transepts and apse by arches, on two of which are depicted the Annunciation and the Presentation of Jesus in the Temple.
Above the chancel rises the dome, supported by a drum decorated with images of evangelists and prophets.
The Christ Pantocrator is represented in the centre of the dome surrounded by angels and archangels. Another Christ Pantocrator is depicted in the apse basin, above a 17th century mosaic of the Madonna between Mary Magdalene and St. John the Baptist.
The Annunciation occupies the arch opening towards the apse. The conformation of the space led the author to place the angel on the left and Mary on the right, separated centrally by the arch of heaven from which the hand of God projects towards the woman the ray of light that, together with the dove, represents divine intervention in the Chapel.
Both Mary and the angel were restored in the 18th century, and both extend along the wall adjacent to them.
Mary’s dwelling is depicted behind her on the south wall as a sumptuous and articulated building. The two figures are united by the Latin inscription that reaches from the angel’s knee to Mary’s knee and reads ‘The Light, the Life and the Way filled you, Virgin Mary, who blessedly believes in the words [of the angel] and does not fill her heart with pride’.
The central apse houses some of the best restored mosaics in the Palatine Chapel. On the back wall there was, as in the side apses, a window, later closed and now replaced by a 17th century mosaic depicting the Madonna, flanked to the north by Mary Magdalene and St. Peter, and to the south by St. John the Baptist and St. James the Greater. All these figures, probably original from the 17th century, show clear signs of restoration.
The inscription below, however, names the archangels Michael and Gabriel, depicted in the inner arch of the apse on either side of the Etimasia. The other two figures below the archangels are St. Gregory the Great and St. Sylvester, both popes.
The large Christ Pantocrator in the apse basin, below which was a window, must have appeared as a source of light, consistent with a decorative programme emphasising the importance of light, repeatedly emphasised in inscriptions, not least the one in Greek and Latin on the book he holds in his left hand (‘I am the light of the world…’). Above Christ is a medallion with the symbols of the Passion, the Hetoimasia: the cross, the crown of thorns, the lance and the sponge soaked in vinegar, while on a cushion at the foot of the cross is the dove of the Holy Spirit. This is the only reference in the Chapel to the death of Christ, recalled by one of the two Latin inscriptions on the cornice of the external arch preceding the apse: ‘The spear, the sponge, the cross, the nails and the crown inspire fear and intense weeping. Sinner weep when you see these things and worship’. However, placed on a royal throne, the instruments of the Passion also become instruments of royal representation, thus clarifying their connection to the Pantocrator.
The mosaics of the dome are considered the best in the Chapel from a technical and artistic point of view.
The structure of the dome itself rests on a cylindrical drum in which four niches, each containing an evangelist, alternate with four biblical characters (David, St. John the Baptist, Solomon and the prophet Zechariah) depicted full-length. Above these, interspersed, are the busts of eight prophets, each with a scroll in Greek containing a passage from their prophecies: Ezekiel, Jeremiah, Jonah, Daniel, Moses, Elijah, Elisha and Isaiah.
The dome proper is decorated with four archangels arranged in a circle (Michael, Gabriel, Uriel and Raphael) and four unidentified angels, which crown a Christ Pantocrator inscribed in a medallion.
Christ is the fulcrum and pivot of the dome’s great wheel of prophets, evangelists and angels. The surrounding inscription in Greek (Thus speaks the Lord: heaven is my throne and earth the footstool for my feet’) explicitly identifies him as Pantocrator. This is an unusual use of this term for a bust of Christ: it usually accompanies the full-length Messiah on a throne, as on the back wall of the Chapel. But in this case his presence in the centre of a dome symbolically suffices, reflecting the structure of the celestial kingdom, the culmination of the entire decorative design of the presbytery. In keeping with Byzantine tradition, the right half of the vow (for the observer) is slightly larger than the left one, but the lack of a centrally positioned parting identifies this figure as being typical of the Norman period.
