The composition of a Book of Hours called for two prayers to the Virgin to follow the passages from the Gospel. Here the first of these prayers, O intermerata, is illustrated by three small interdependent miniatures that form an ensemble.
In the upper part the Virgin appears on the moon's crescent, surrounded by flames and radiant light. The figure seems to have been inspired by a miniature in the Boucicaut Hours in which a Virgin in Majesty is shown in a similar pose and surroundings.
On the lower left, a crowned and haloed sibyl points to the Virgin. In the Middle Ages Virgil's line from the Eclogues, "iam redit et virgo, " was interpreted as "already the Virgin returns," and medieval artists often represented a sibyl announcing the birth of Christ to the pagans.
In the opposite scene the Limbourgs have shown the Emperor Augustus kneeling to praise the Virgin and Child in a position similar to that adopted at a later date by Rogier van der Weyden in the right wing of the Bladelin Altarpiece in Berlin.
The Emperor's large white beard, strange diademed hat, voluminous blue robe, and curved sword at his side all recall the representation of the oldest of the three kings in the Meeting of the Magi (folio 51v).
The unusual diadem seems to indicate the inspiration given the artists by Manuel II Paleologus, Emperor of Constantinople, who spent two years in France at the beginning of the fifteenth century. It is, in fact, exactly like the diadem the Emperor John VIII Paleologus, his son, wears in a medal executed by Pisanello (Paris, Bibliothèque Nationale).
The Limbourgs were the first artists outside of Italy to treat the legend alluded to here, which had originated in Rome. According to it, Augustus, whom the Senate wished to deify for having restored peace to the world, happened to consult the Tiburian Sibyl on the day of Christ's birth.
The prophetess saw a circle of gold appearing around the sun, from the middle of which radiated a virgin holding a child, and heard a voice saying, "Here is the altar of the Son of God."
Showing the apparition to the Emperor, the sibyl said to him, "Today a king is born who will be more powerful than you." Upon hearing this, Augustus renounced all divine honors and fell upon his knees to worship the Son of God.

small image (25KB) --- large image (236KB) --- The Virgin and Child (large) (228KB) --- The Sibyl and Augustus (large) (291KB)