The oratory at Germigny-des-Prés was built by Bishop Theodulf of Orléans in 806 as part of his palace complex within the Gallo-Roman villa in Germaniacus. Theodulf, who was also abbot of the neighboring monastery of Saint-Benoît-sur-Loire, was a Spaniard and one of the most celebrated men of letters in the Carolingian Empire court of Charlemagne. The Carolingian architecture of his palace complex at Germigny-des-Prés was in a general sense modelled on Charlemagne's Palace of Aachen. All except the oratory was destroyed by the Vikings within a century of construction.
As reconstructed by Theodulf in 806, the oratory took the form of a rough square with single apses in the middle of the north, south, and west sides, and three apses on the east side. Internally, the space took the form of a Greek cross: a high central tower filled the central bay, barrel vaults extended off in the north, south, east, and west bays, while in the corner bays there were low domes carried on squinches. This plan type was later to become standard in Byzantine architecture.
The great treasure of the church is the mosaic of the Ark of the Covenant, on the ceiling of the apse. This mosaic is the only surviving Byzantine mosaic in France, although traces of mosaics elsewhere on the roof indicate that it was part of a wider decorative scheme. The mosaic owes its preservation to being plastered over at the time of the French Revolution; it was rediscovered in the middle of the 19th century. The mosaic is one of the few remaining artworks from the period of the Iconoclasm which convulsed the Eastern Church during the 8th & 9th centuries, but which also impacted on Western Christendom. Traditionally, the place occupied by this mosaic was reserved for images of the Virgin Mary, enthroned as Queen Of Heaven, with the Christ child on her knee, and with an attendant angel on either side. These angels pointed out the divine status of the figures between them.
The artist working at Germigny (who was obviously au fait with Byzantine practice, if not actually Greek himself) has replaced the portrait of the Virgin, Mother of Christ, with an equivalent but symbolic representation. The Ark of the Covenant contains ‘manna’, the miraculous bread given from Heaven to the Israelites in the desert; this was interpreted as a prefiguration of the Virgin, who bears Christ, the Holy Bread. The mosaicist, and Théodulf d'Orléans, seem to have held a middle course, balanced between extreme iconoclasm and the partisans of images such as John of Damascus. This moderate position is exactly that which the theologians appointed by Charlemagne in the Council of Frankfurt (794) decided upon.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.