The Duke of Norfolk, Elizabeth's principal Commissioner, was one of the most powerful of all her nobility, and, since Mary's arrival in England, he had formed the ambitious project of ascending the Scottish throne by means of a marriage with her. With this view, he had already engaged extensively in secret intrigues, and had, in particular, prevailed on Lethington to approve of his plans, and promise him his support. But Robertson asserts further, that soon after his arrival at York, he won over Murray also to his views, and persuaded him to keep back, for a time, the heaviest part of his accusation against Mary, that her character might not be so fatally blackened. The historian's assertion, however, is unsupported by the evidence he adduces in its favour, his references to Anderson, to Goodall, and to his own Appendix, being quite unsatisfactory. Whatever promises Murray may, at a subsequent date, have made to Norfolk, it clearly appears that no charge against Mary was delayed one hour at York, in consequence of any understanding between these two noblemen. It had been all along the Regent's determination, not to have recourse to the letters, if he could make out a case without them; and even after he perceived that he would require their aid, he did not produce them openly, till they had been first shown privately to the English Commissioners, and their opinion obtained concerning them. It was on the 4th of October that the conference commenced; and on the 10th, Lethington, Macgill, and Buchanan, in a secret interview with Norfolk, Sussex, and Sadler, laid before them the mysterious documents. The nature of their contents was communicated to Elizabeth on the 11th, and she was requested to mention in reply, whether, when publicly adduced and authenticated, they would be sufficient to secure Mary's condemnation. Murray, therefore, cannot at this time, have entered into any agreement with the Duke of Norfolk; for, so far from keeping back his box-full of letters, he was nervously anxious to ascertain, as speedily as possible, whether Elizabeth would attach any weight to them, or allow them to be branded as palpable forgeries. Had Robertson attended a little more to dates, he would have discovered, that so far from wishing to favour the views of the Duke of Norfolk, Murray informed Elizabeth regarding the letters and their contents, on the very day on which he gave in his first "Answer" to Mary's Commissioners. Nor had these letters been entirely unheard of till now; for, though they had never been exhibited, they had been expressly alluded to nearly a year before, in an act published by the Lords of Secret Council, on the 4th of December 1567, in which it was asserted, that by the discovery of certain of the Queen's private letters, sent by her to the Earl of Bothwell, it was "most certain that she was art and part of the actual device and deed of the murder of the King."[162] The same assertion was subsequently