Abstract The Lost Apse Mosaic in Lyon Cathedral in Light of its Titulus . Proposed Iconography and Argument for a Carolingian Attribution The now-lost apse mosaic of the ancient cathedral of Lyon is attested exclusively through the ten hexametric verses of its titulus , transcribed in the ninth century by Mannon, a disciple of the deacon Florus. In accordance with the ekphrastic tradition, the text poetically evokes the theophanic vision once displayed above in the conch, providing crucial evidence for reconstructing its iconographic program. The composition likely comprised a Maiestas Domini , the Apostolic College, the Heavenly Jerusalem, the four rivers of Paradise, the Agnus Dei , and possibly John the Baptist (perhaps represented symbolically through the allusion to the River Jordan). This study proposes a hypothetical visual reconstruction of these elements and their spatial configuration within the apse, highlighting the dialectic between figural representation and liturgical implications. Furthermore, several arguments are presented in support of assigning the titulus (and the mosaic work of which it was part) to Florus’s initiative. This is not an obvious attribution, considering the numerous references to early Christian culture present both in the verses of the inscription and in the iconographic subjects mentioned therein.
Simone Piazza (Tue,) studied this question.