The biographers of Blessed Peter Canisius for the most part claim him as the hero of this expedition, which was in fact entrusted to several delegates, of whom the principals were the veteran Carmelite provincial, and Johann von Isenburg. Canisius was deputed to go first to Liege, and to beg that its bishop, George of Austria, son of Maximilian I., and uncle to the Emperor, would facilitate their journey, the country through which they would have to pass being invested with the enemy's troops. During the time which he spent at Liege, Canisius completely won the heart of the prince-bishop, who ordered him to preach in his cathedral and in his private chapel, expressing himself greatly edified with what he had heard. His visit being unavoidably prolonged, Canisius gave the Spiritual Exercises, took part in theological conferences with the Lutherans, visited the sick in the hospitals, and catechised the children. Crowds followed him wherever he went, and there was but one opinion of his learning, eloquence, and charity.
It is probable that on his return to Cologne, having given an account of his mission, he started with the other delegates for Worms.
Writing to the coadjutor Adolf, on 6th December, Billick says that at Mainz they heard that all the roads were occupied by the enemy. In order to avoid all appearance of an embassy they left their baggage behind them at Mainz, and being advised by the vicar-general, Scholl, the Carmelite separated from his companions, and hastened on alone to Worms to present his letters to the Dean of St. Andrew's. Here he lay hidden for four days, in the greatest anxiety and doubt as to his further progress. Neither he nor his advisers could hit on a safe mode of continuing the journey, as it was known that separate parties of defeated Schmalkaldians were making their retreat good by various roads back to the Rhine. To add to his alarm and embarrassment Billick discovered that his horse had been rendered useless by a mysterious wound, so that he had reason to think he had been betrayed. Just then, however, he received information that the imperialists were in hot pursuit of the Schmalkaldians, and having bought another horse from a Jew, he set out for Speyer. At Speyer he fell in with a nobleman belonging to the imperial army on his way back to the camp, and Billick joined him, without however revealing his name or his mission, so necessary was it to regard every stranger as a possible enemy.
At last the road to the Emperor was open, and the delegates, who all arrived simultaneously at Krailsheim on the 5th December, were received by Cardinal Granvelle. The object of their embassy was then speedily attained. Charles V. issued a mandate, ordering the Landtag to assemble at Cologne on the 24th January following; and at the date fixed two imperial commissioners appeared to conduct the proceedings.
On the same day the coadjutor Adolf was inducted as archbishop, in spite of the opposition of a large number of the representatives of the Landtag, who, however, gave in their adhesion by the end of the month. Hermann still offered a futile resistance, but on 28th February 1547 was at last forced from a position that had become untenable. He died on the 15th August 1552.
During these proceedings Peter Canisius had attracted the attention of Cardinal Otto Truchsess, who desired to have him as his second theologian at the Council of Trent, Father Le Jay having already been sent there as first theologian to that prelate. The cardinal, in a letter to St. Ignatius, laid stress on the circumstance of Peter's intimate acquaintance with the state of religion in Germany, and on his being able therefore to suggest to the Council the best means of meeting the prevalent evils. These reasons had great weight with St. Ignatius, and scarcely had the young Jesuit returned to Cologne, when he received orders to set out for Trent. Great was the lamentation among the burghers of Cologne. All whom he met in the streets greeted him with tears and supplications not to depart out of their midst. His leaving, they declared, would mean triumph to the enemies of the Church. The university conferred on him unanimously the title of doctor of divinity as a proof of their gratitude, esteem, and regret at his loss. The clergy and senate presented him with two precious relics—the heads of two of the martyred companions of St. Ursula.
At Trent Canisius found four of his religious brethren, and joined them at their lodgings in the hospital. Here the five Jesuits followed the special rule of life which St. Ignatius had sent to them. "Three things I wish you to bear in mind," he wrote:—
"(1) at the sessions of the Council the greatest glory of God, and the general good of the Church; (2) outside the Council your fundamental principle to labour for the salvation of souls, a matter that lies especially near my heart in this your journey; (3) when at home not to neglect yourselves." He recommended them to behave as prudently as possible at the Council, not to speak hastily, and to be ever on the side of peace. Every evening they were to confer with each other on the day's proceedings, and to make resolutions for the morrow. "Moreover," he continued, "you will allow no opportunity to escape you of acquiring merit in the service of your neighbour. You must always be on the watch to hear confessions, to preach to the people, to instruct the little ones, to visit the sick." In their sermons they were to avoid controverted dogmas, and to lay stress on all that appertained to the reform of morals, and obedience to the Church.
The meetings of the Council being adjourned till 1550, Canisius was called to Rome, where he remained for five months, under the personal guidance of St. Ignatius himself, who submitted him to the most humiliating trials in order to prove his virtue. He sent him to beg and to preach in the most frequented parts of the city, and to nurse the sick in the hospitals, where he was day and night at the beck and call of exacting officials, who set him to perform the most loathsome tasks, and often curtailed his sleep and food. St. Ignatius would then cause inquiries to be made at the hospitals concerning the behaviour of his novice under this kind of treatment.
In the spring of 1548, Canisius was sent with eleven companions to Messina, where the Viceroy, Don Juan de Vega, had founded a college. On the eve of their departure St. Ignatius put to them four questions in writing. Canisius answered the questions thus:—