Cesare Nebbia, The Birth of the Virgin Mary
Cathedral of Santa Maria Assunta, Orvieto, Italy
The main scene in the triangle is a typical Birth of the Virgin image, with Anne in bed in a comfortable indoor setting and Mary being bathed by midwives. The baby has already adopted the "orant" posture seen in early images of the Virgin Mary.
The two persons left and right of the triangle are most likely Mary's parents Joachim and Anna, whom an angel instructed to rendezvous at the Golden Gate (Gospel of the Nativity of Mary 3-4, Pseudo-Matthew 3 and Protevangelium 4). The wind-blown cloth on Anna's head would thus be the "headband" offered her in chapter 2 of the Protevangelium.
It is true that the age of the two figures is a problem. The legends say that Joachim was visited by the angel during the 20th year after he married Anna at the age of 20. But the man in this image looks well above the age of 40 and the woman well below, so it is conceivable that the man is Joseph arriving at the Temple for the test of the rods (Protevangelium 8-9, Pseudo-Matthew 8, and the Gospel of the Nativity of Mary 7-8). But the legends say nothing of Mary's being visited by any angel other than Gabriel at about that time, and the angel here is certainly not Gabriel. It is more likely, therefore, that the artist simply applied to his Joachim the white hair and walking staff of St. Joseph's iconography.
The angel in both the Anna and Joachim images points to the left, probably because the mosaic is on the right side of the façade.
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More of the Birth of Mary
Photographed at the cathedral by Richard Stracke, shared under Attribution-NonCommercial-ShareAlike license.