Thirty foundations of the Augustinians in Saxony had accepted the reform begun by Andrew Proles in the fifteenth century, and had separated themselves definitely from the unreformed houses of the order in Germany. They were subject immediately to the general of the order, whose vicar at this time in Saxony was the well-known Humanist, Staupitz.[5] The latter was anxious to bring about a reunion between the two parties and to have himself appointed as superior; but the party who stood for the strict observance were opposed bitterly to such a step, and determined to send a representative to Rome to plead their cause. The fact that they selected so young a man as Luther to champion their interests is a sufficient proof of the position which he had won for himself amongst his religious brethren. He was looked up to already as an ornament of the order, and his selection for this highly important mission served to increase the over-weening pride and self-confidence that had manifested themselves already as weak spots in his character. Accompanied by a companion of his order he started on his long journey across the Alps. As he reached the heights of Monte Mario and surveyed the Popes he fell on his knees, according to the custom of the pilgrims, and hailed "the city thrice sanctified by the blood of martyrs." He had looked forward with pleasure to a stay in Rome, where he might have an opportunity of setting his scruples to rest by a general confession of his sins, but, unfortunately, his brother Augustinians in Rome and those with whom he came most in contact seemed to have been more anxious to regale him with stories about the real or imaginary scandals of the city than to give him spiritual consolation or advice. Yet in later life, when he had definitely separated from the Church and when he was most anxious to blacken the character of Rome and the Popes, it is remarkable that he could point to very little detrimental to them of which he had personal knowledge, and was forced to rely solely on what had been told him by others. Nor did he leave Rome as a declared enemy of the Papacy, for even so late as 1516 he defended warmly the supremacy of the Pope as the one safeguard for the unity of the Church.[6] Many of his biographers, indeed, assert that, as he stood by the Scala Sancta and witnessed the pilgrims ascending on their bare knees, he turned aside disgusted with the sight and repeated the words of St. Paul, "the just man lives by his faith"; but such a statement, due entirely to the imagination of his relatives and admirers is rejected as a legend by those best qualified to judge.[7] The threatened union of the strict and unreformed that had occasioned Luther's journey to Rome was abandoned; but it is worthy of note that Staupitz had succeeded in detaching him from his former friends, and that he returned to Germany a convinced and violent opponent of the party of strict observance, who had sent him to Rome as their representative. During his stay in the city there is good reason for believing that on his own behalf he sought for permission to lay aside his monastic habit and to devote himself for ten years to study in Italy, but his request was refused on the ground that it was not supported by the authority of his superiors. This petition was probably the foundation for the rumours that were circulated in Germany by his opponents that while in Rome he endeavoured to have himself "secularised" and to obtain a dispensation to marry.

On his return to Germany he devoted himself once more to the study of theology in preparation for the doctorate which he won at Wittenberg in 1512. Almost immediately he was appointed professor at the university and undertook to lecture on the Psalms. His eloquence and his imagination, his retentive memory enabling him to illustrate his texts by parallel passages drawn from the books of the Old Testament, and in a certain way his exaggerations, his strength of diction, and his asperity of language towards all with whose views he did not find himself in agreement, made his lectures most popular at the university, and filled his hall with an eager and attentive audience. Amongst the students Luther had no rival, and even the few professors who were inclined to resent his methods and his views were captivated by the magic influence of their brilliant young colleague. The Augustinians, mindful of the honour he was achieving for their order, hastened to appoint him to the important position of district vicar (1515), while the Elector Frederick could not conceal his delight at having secured the services of so capable a professor for the new university.