The so-called letter of St. Ulrich of Augsburg against clerical celibacy, with the account of 3000 (6000) babies’ heads found in a pond belonging to St. Gregory’s nunnery in Rome, is admittedly one of the most impudent forgeries found in history and emanated from some foe of Gregory VII and opponent of the ancient law of celibacy. Luther brought it out as a weapon in his struggle against celibacy, and, according to Köstlin-Kawerau, most probably the Preface to the printed text published at Wittenberg in 1520 came from his pen.[265] The manuscript had been sent to Luther from Holland. Emser took him to task and proved the forgery, though on not very substantial grounds. Luther demurred to one of his arguments but declared that he did not build merely on a doubtful letter. In spite of this, however, the seditious and alluring fable was not only not withdrawn from circulation but actually reprinted. When Luther said later that celibacy had first been introduced in the time of St. Ulrich, he is again speaking on the authority of the supposititious letter. This letter was also worked for all it was worth by those who later took up the defence of Luther’s teaching.[266] To take one single example of Luther’s waywardness in speaking of Popes who were almost contemporaries: He tells us with the utmost assurance that Alexander VI had been an “unbelieving Marane.” However much we may execrate the memory of the Borgia Pope, still so extraordinary an assertion has never been made by any sensible historian. Alexander VI, the pretended Jewish convert and “infidel” on the Papal throne! Who could read his heart so well as to detect an infidelity, which, needless to say, he never acknowledged? Who can credit the tale of his being a Marane? * * * * * When, in July 14, 1537, Pope Paul III issued a Bull granting an indulgence for the war against the Turks, Luther at once published it with misleading notes in which he sought to show that the Popes, instead of linking up the Christian powers against their foes, had ever done their best to promote dissensions amongst the great monarchs of Christendom.[267]