Pius VI and Pius VII were the two Popes whose pontificates coincide with the era of the French Revolution and the Napoleonic conquests. Their unhappy stories are bound up with the history of the Quirinal Palace, which fronts upon the Monte Cavallo; and they form a pitiful contrast to the life of that masterful old Pontiff Sixtus V, in whose reign the history of the palace and the modern piazza begins. Sixtus, having destroyed, for no reason now known, the old mediæval papal palace of the Lateran, decided to rebuild it to suit himself, but found, as the new building progressed, that it was too cold and uncomfortable for a residence. So the Lateran, which had been the papal palace since the seventh century, holding its own against the magnificence and enormous size of the Vatican, was gradually abandoned as a residence, and Sixtus established himself in the Quirinal. Sixtus V, for all his detestation of classic statuary, must have shared with his people the profound respect and admiration always aroused by the Dioscuri. These colossal groups were among the few rare works of antiquity which were cherished by the semi-barbarous Romans of the Middle Ages, and the web of fable spun about them during those dark years proves the hold they had over the superstitious imagination of the times. “Nothing is beyond question” about them, says Lanciani, except that they once adorned the temple which the Emperor Aurelian built to the sun on his return from the conquest of Palmyra in 272. This most magnificent of all Roman temples, to quote the same great modern authority, became a quarry for building materials, even as early as the sixth century. The Emperor Justinian is said to have taken some porphyry columns from it to adorn the Church of St. Sophia in his new capital of Constantinople. The Dioscuri must have been discovered later in the Baths of Constantine. The relative positions of the horses and their tamers were ascertained from antique coins. Modern authorities are of the opinion that they are Roman copies of Greek originals, and they are counted among the great inheritances from imperial Rome. It is curious to trace the working of the mediæval intelligence, groping its way through mysticism and allegory to find some explanation for the undeniable impression made by these heroic figures upon the minds of all who behold them. The attempt to read into them some abstruse ethical meaning was abandoned long ago, and the world of to-day accepts the Dioscuri frankly for what they are, admiring, with a wonder not unmixed with despair, the unreclaimable art of ancient Greece. “Ye too marvellous Twain, that erect on the Monte Cavallo Stand by your rearing steeds in the grace of your motionless movement, Stand with upstretched arms and tranquil, regardant faces, Stand as instinct with life, in the might of immutable manhood-- Oh, ye mighty and strange--ye ancient divine ones of Hellas!”