Unless the society is stagnant, like China, its social life is marked by changes of power. The revolutionary classes succeed, and replace the old rulers; whereupon we note at once a change in their art. Those who were dissatisfied now find peace; those whose emotions overwhelmed them now find themselves able to order their thoughts; those who were interested in what they had to say now achieve triumphs of technique; in short, those who were producing an Art of Power now begin to produce an Art of Beauty. And so we are in position to understand what happened to Christian art, when the martyrs and the saints broke into “good society.” The Roman Empire fell about five hundred years after Christ, and for another five hundred years the Italian peninsula was a battle-ground of invading barbarian hordes. When finally things settled down, the land was held by a great number of feudal princes and plundering groups, having their lairs in castles and walled cities. Christianity was the official religion, and abbots and bishops and popes were robber chiefs commanding armies. In between their military campaigns they took their pleasures like other princes; and among their pleasures were those of art. The inner emotions which Christianity cultivated were free to those who sought them in monks’ cells and hermits’ caves, but they could not be purchased nor rented out, and they wilted in the atmosphere of palaces and courts. So gradually we find Italian religious art undergoing a change. The saints become gentlemen of refinement wearing scholars’ robes; Jesus becomes a heavenly prince, in spotless linen garments and a golden crown, casting benevolent looks upon the clergy; the Virgin Mary becomes the favorite mistress of a duke or abbot or pope--or perhaps the painter’s own mistress. This latter arrangement is common, for business reasons easy to understand. The lady is at hand, and has nothing to do while the painter is painting; he gets the service of a model free, he flatters his lady love’s vanity, and at the same time he keeps her safe from other painters. So the poison of luxury creeps into what is supposed to be religious art; and we see the symbols of martyrdom and holy sacrifice employed to glorify the vanities and cloak the vices of the predatory classes.