The décor of the temple
Immediately next to the southern entrance can be seen the marble slabs that covered the lower part of the walls, both in the presbytery and in the main body of the church. It has been ascertained that this wall covering was closely linked to a marble floor with a geometrical motif of rectangular slabs and hexagonal and triangular tesserae, in black and white, forming a star-shaped pattern, similar to the one recomposed in the main body of the building using the antique elements. In the north-east corner of the presbytery, on the right of the wall facing the entrance, there remains the preparation for this floor in which the imprints of the tesserae can be seen. The present stone paving is the result of recent refurbishment carried out in the 20th century to restore the original level of the presbytery, which had perhaps already been raised in the Middle Ages. After the reconstruction work a sarcophagus standing on the raised floor, along the presbytery partition, under the north aisle, was dismantled; it had been made by putting together old fragments carved in the second half of the 8th century as parapets for a pulpit, which can now be admired hanging on the wall. The sarcophagus is known as the “Tomb of Piltrude”. Also in the north-east corner of the presbytery we can see some cream coloured plaster with a marble effect, extending over the east and north walls, and which seems to have been applied before the preparation of the floor and the marble covering of the wall. It might be a remnant of an early decorative phase of the chapel, with a different floor at a lower level, or a preliminary finish from the long series of construction of the Temple, which may also have included changes while work was in progress. These changes in the project may also explain the unusual location of the consoles over the pillars which project quite far out from the wall, supporting the vaults on the east side. The high parts of the presbytery have only limited traces of the antique decoration which must have been very rich. The presence of nails on the preparatory layer still adhering to the barrel vaults at the sides suggest the existence of a plaster or mosaic covering. A mosaic certainly covered the upper strip of the back walls, as is shown by a small portion preserved in the south aisle, near the window, under protective glass. Between the decoration of the vaults and the marble slabs, the ornamentation of the east sector probably included two other stucco friezes enclosing a painted inscription that extended beyond the presbytery as far as the north and south niches of the main body. There remain only limited fragments of the inscription, composed in verses – twenty-four hexameters – and written in large white and ochre letters on a purple background, the best preserved of which can be seen on the north wall of the main body. Besides invocations of the Virgin and the Redeemer, the legible text mentions tragic events and recalls the pious architects of the building, unfortunately without giving their names. So the inscription must have been a dedication, celebrating the building of the Temple, adopting the antique model of public propaganda to indicate the noble, presumably royal rank of the patrons who promoted its construction. This is clear also if we observe the stucco and fresco decorations of the main body which certainly indicate the work of highly skilled craftsmen and are points of reference in the process which, in the late Longobard period, led to the creation of a courtly art form promoted by the highest spheres of the kingdom. Unique on the artistic scene in Longobard Italy, these decorations can be admired on the west counter-façade, right in front of the presbytery, where there remains the original articulation in three ornamental zones that also featured on the north and south walls. Above the high marble base, now hidden by the wooden choir, run the frescoes of the central strip, now visible only at the sides of the entrance arch, with figures of Saints against a frame with plant decoration. The lunettes over the arches were frescoed too: on the west we can see the figure of Christ Blessing between the Archangels Michael and Gabriel, on the south wall, the badly spoilt representation of a Madonna and Child between two Archangels; the fresco in the lunette on the north wall is no longer legible. With their formal elegance, these frescoes are considered one of the finest expressions of eighth-century painting, the work of artists linked to the leading experiences of Greek-Byzantine painting of the period. The stucco decorations are exceptional, starting from the architrave and the arch with vine branches in openwork, adorning the main entrance. In these works there is an echo of the iconographic repertoire and naturalistic rendering, combined with the search for a plastic effect using chiaroscuro, that comes from Early Christian and Byzantine art.
The other stucco ornaments also refer to the same tradition: the string courses with floral motifs, in the centre of which were glass ampoules, or the pilaster strips with capitals and archivolt surrounding the windows, but above all the sequence of saints and martyrs standing alongside the windows. As well as those that we can see on the west side, six other similar figures must originally have adorned the spaces between the windows on the north and south walls. On the east wall, over the triple arch of the presbytery, it is presumed that there may have been a larger sculpture, representing the Annunciation or Christ in Majesty.
The female figures that remain, slightly taller than life size, are all complete with halos. The two immediately at the sides of the window, shown in a slightly three-quarter view in an act of devotion, in a white tunic and palla, or cloak, raised to cover the head, are pointing to the window, the source of light which symbolises Christ, the Saviour. The other four, viewed from the front, richly dressed and adorned with a gem-studded collar and diadem, hold the crown of martyrdom and the cross in their hands.