Together with Sassetta, Giovanni di Paolo was one of the leading Sienese painters in the fifteenth century. So strong was the hold on Sienese art of its great fourteenth-century masters - Duccio and his followers - that both Giovanni di Paolo and Sassetta consistently harked back to earlier models.Giovanni's dual allegiance to the modern and the old can clearly be seen in the four predella panels of Scenes from the Life of Saint John the Baptist at the National Gallery in London, of which Saint John retiring to the Desert is likely to have been the second from the left. The other panels represent the saint's birth, the Baptism of Christ, and the Feast of Herod at which Salome's dance and Herod's reward for it brought about the decapitation of the saint. The story of Saint John the Baptist is told in the Gospels and in legend, and its pictorial tradition was well established by the fifteenth century. The altarpiece of which these panels formed the predella - a box-like supporting element for the main painting - was a large Madonna and Saints perhaps painted for the church of Sant'Agostino in Siena (now in the Metropolitan Museum, New York).This scene shows the Baptist as a child, carrying his few needs on his shoulder, leaving the familiar city gate to make his way up into the wilderness. Just to his right we see him again, several miles away, but not reduced at all in scale: a giant walking up the steep mountain path. The head and torso of the two figures are almost identical, but as John climbs he slings his bundle over the other shoulder. Thus the spectator has moved with St John, and the foreground landscape becomes the vista opening up below as the child climbs. The picture is about renouncing the city, leaving behind the man-made grid of cultivated fields, its beautiful patchwork of contrasted greens, for a world of wilder forms. Higher up, we glimpse a yet further region - a blue-and-white ice realm, across a dark river, extending to the curved rim of the horizon - all laid in with a scintillating economy of mark.Charming are the borders of roses painted entirely realistically on either side. Curiously, these are seen from below, as by a viewer at eye level with the lower bud on each branch.