In no period of the Middle Ages can we find personalities more striking than those zealous upholders of the papal prerogative, Gregory VII and Innocent III--a statement which applies equally well to the great champions of the empire, Frederick I and Frederick II. Frederick Barbarossa attained his exalted position when scarcely thirty; his illustrious namesake at an even earlier age. Both therefore entered the contest with all the vigor and enthusiasm of their young manhood. Although Gregory VII and Innocent III were somewhat farther advanced in life, they too had lost none of their youthful ardor and enthusiasm as they had risen rapidly to high position, the one becoming papal counsellor before he was thirty, the other elected pope at thirty-eight. These men represent some of the best products of their times, in character, physique, scholarly attainments and native ability. Frederick II even foreshadows in character rulers like Henry VIII and Louis XI, who lived more than two centuries later. Alike in some respects, what contrasts they present in others. So faithfully have the chroniclers performed their tasks that it is comparatively easy to call them up and make them pass in review before us. Hildebrand, unimposing in appearance, but passionate and indomitable; Henry IV, intelligent, but violent; the tall, fair-haired, princely Barbarossa; the thin, but well-proportioned, Frederick II, of studious mien; and finally the majestic Innocent III, now giving way to bursts of anger, and now plunged into fits of deep melancholy. The principles which these men represented could not have had better advocates. The Issues.