Thenceforward the popes, whether they wished it or not, were to be serious men. As the Reformation spread through England, the Low Countries, France and Germany, the papacy set its house in order and prepared to fight, not for its temporal supremacy, as in the mediæval struggle with the Emperors, but for its spiritual authority. It was at this point that there came to its aid a new force, a force whose influence has never yet been accurately measured. In 1539, just before the close of Luther’s life, Ignatius Loyola founded the Society of Jesus. This was in the time of Paul III. Four pontificates later, under Pius IV, the Jesuits, as Calvin was the first to call them, furnished the sensational element in the second sitting of the Council of Trent; and in 1572, when Ugo Boncompagni became Pope, under the title of Gregory XIII, the order made its appearance on the world’s stage as the recognized director of the church militant. The Jesuits were the keepers of this Pope’s conscience, and the history of his pontificate is the first chapter in the history of Jesuit rule. For them the Pope erected the present building of the Collegio Romano, founded in Loyola’s time; for them he founded the German and English colleges at Rome, and, according to Ranke, “probably there was not a single Jesuit school in the world which had not to boast in one way or another of his bounty.” The chief architects of the time were put at their disposal. Vignola designed and built for them the vast Church of “the Gesù”; and as he died while the work was in progress, his distinguished pupil, Giacomo della Porta, turned from the making of beautiful fountains and completed the cupola and façade. The latter also built the high altar in that church, and in its construction showed once more that love of rare marbles which is so distinctive a feature in the Colonna and other fountains of his creation. Gregory XIII had begun life as a Bolognese lawyer. He had been called to Rome by Paul III the very year Loyola founded the Society of Jesus. He had gone to Spain as Papal legate under Paul IV, had been created cardinal by Pius IV, and at the age of seventy was made Pope. His life had peculiarly fitted him to appreciate Jesuit ideals. His belief in educational institutions, his keen interest in geography and the remote corners of the earth, the correctness of his private life after his elevation, his previous worldliness, and his secular training, all combined to make him the Jesuit Pope. The Roman Church remembers him as the builder of the Gregorian Chapel in St. Peter’s, the reformer of the calendar, the reorganizer of a great body of ecclesiastical law, and the patron of the Order of the Jesuits. To Protestants he remains the Pope who sang “Te Deums” for “the St. Bartholomew.”