Stories from the Infancy of Christ and from the Life of Mary
The sequence of events around the birth of Christ begins with the Annunciation of the Virgin on the west side of the capital group which is supported by four columns. Gabriel and the Virgin are spatially separated by arches on columns, around which a curtain is looped. As the messenger of God, Gabriel bears a caduceus in his left hand, while the right is raised in the gesture of annunciation. Mary holds a spindle in her hand.
Architectural shorthand and arches are a customary representational principle in Annunciation scenes and they turn up in all types from the earliest surviving examples on. In exactly the same way the Virgin with the distaff is a well-known topos of the Annunciation in Byzantine art. This is based on the apocryphal proto-gospel of Jacob (10, 1-11, 13) – which dates to the middle of the second century – wherein Mary was chosen by the high priest to fashion a scarlet and purple curtain.
On the south side the arches with the Visitation and the Annunciation to Joseph continues the narrative. The east side shows the Nativity, Joseph's dream, and the Annunciation to the Shepherds, while the north side displays the journey and the Adoration of the Magi.
The narration is integrated into the structure of the Corinthian style capital. The soffit of the impost block, moreover, is decorated with alternating rosettes and consoles in the form of volutes. Prominent in the same way is the classicizing formal vocabulary in the abbreviated architecture as well as the form and clothing of the figures.