seen at Fontainebleau by Cassiano dal Pozzo. In 1806, the French restorer Fr Hacquin transferred the Louvre Virgin of the Rocks from its panel onto canvas. For a brief time in 2011–12 it was hung with the London painting as part of an exhibition in the National Gallery on Leonardo's activity as painter to the court of Ludovico Sforza. Side panels The two panels from the completed altarpiece containing figures of angels playing musical instruments were acquired by the National Gallery, London in 1898. Subject The subject of the two paintings is the adoration of the Christ child by the infant John the Baptist. This subject relates to a non-Biblical event which became part of the medieval tradition of the holy family’s journey into Egypt. The Gospel of Matthew relates that Joseph, the husband of Mary, was warned in a dream that King Herod would attempt to kill the child Jesus, and that he was to take the child and his mother and flee to safety. There are a series of non-Biblical narratives that relate to the journey to Egypt. One of these concerns Jesus’ cousin, John the Baptist, whose family, like that of Jesus, resided in the town of Bethlehem where the Massacre of the Innocents was to take place. According to legend, John was escorted to Egypt by the Archangel Uriel, and met the holy family on the road. The Louvre website refers to the angel in the painting as "Gabriel" (but the description of the painting in the Louvre still refers to Uriel). This accords with the Apocryphal gospel of John the Baptist, which describes his removal from Bethlehem as by Gabriel rather than Uriel and does not mention the meeting on the road to Egypt. The subject of the Virgin Mary with the Christ child being adored by John the Baptist was common in the art of Renaissance Florence. John the Baptist is the patron saint of Florence and has often been depicted in the art of that city. Those who painted and sculpted the subject of the Mary and child with St John include Fra Filippo Lippi, Raphael, and Michelangelo. In both paintings the scene is depicted taking place against a background of rock formations. While scenes of the Nativity were sometimes depicted as taking place in a cave, and Kenneth Clark points to the existence of an earlier rocky landscape in an adoration painted