Mary’s attitude as regards the Casket Papers is now, I think, intelligible. There was a moment, as we have seen, during the intrigues at York, when she consented to resign her crown, and let the matter be hushed up. From that position she receded, at Norfolk’s desire. The Letters were produced by her adversaries, at Westminster and at Hampton Court. She then occupied at once her last line of defence, as she had originally planned it. If allowed to see the documents put in against her, and to confront her accusers, she would produce evidence in black and white, which would so damage her opponents that her denial of the Letters would be accepted by the foreign ambassadors and the peers of England. ‘Her proofs will judicially fall out best as is thought,’ Sussex wrote, and he may have known what ‘her proofs’ were.
If we accept this as Mary’s line, we can account, as has already been hinted, for the extraordinary wrigglings of Lethington. At York, as always, he was foremost to show, or talk of the Casket Papers, in private, as a means of extorting a compromise, and hushing up the affair: publicly, he was most averse to their production. Whether he had a hand in falsifying the papers we may guess; but he knew that their public exhibition would make Mary desperate, and drive her to exhibit her ‘proofs.’ These would be fatal to himself.
We have said that Mary never forgave Lethington: who had been the best liked of her advisers, and, in his own interests, had ever pretended to wish to proceed against her ‘in dulse manner.’ Why did she so detest the man who, at least, died in her service?
The proofs of her detestation are found all through the MS. of her secretary, Claude Nau, written after Lethington’s death. They cannot be explained away, as Sir John Skelton tries to do, by a theory that the underlings about Mary were jealous of Lethington. Nau had not known him, and his narrative came direct from Mary herself. It is, of course, worthless as evidence in her favour, but it is highly valuable as an index of Mary’s own mind, and of her line of apology pro vita sua.
Nau, then, declares (we have told all this, but may recapitulate it) that the Lords, in the spring of 1567, sent Lethington, and two others, to ask her to marry Bothwell. Twice she refused them, objecting the rumours about Bothwell’s guilt. Twice she refused, but Lethington pointed out that Bothwell had been legally cleared, and, after the Parliament of April, 1567, they signed Ainslie’s band. Yet no list of the signers contains the name of Lethington, though, according to Nau, he urged the marriage. After the marriage, it was Lethington who induced the Lords to rise against Bothwell, with whom he was (as we elsewhere learn) on the worst terms. Lethington it was who brought his friend and kinsman, Atholl, into the rising. At Carberry Hill, Mary wished to parley with Lethington and Atholl, who both excused themselves, as not being in full agreement with the Lords. She therefore yielded to Kirkcaldy; and Bothwell, ere she rode away, gave her the murder band (this can hardly be true), signed by Morton, Lethington, Balfour, and others, bidding her keep it carefully. Entrapped by the Lords, Mary, by Lethington’s advice, was imprisoned in the house of the Provost of Edinburgh. Lethington was ‘extremely opposed’ to her, in her dreadful distress; he advised imprisonment in Loch Leven; he even, Randolph says, counselled the Lords to slay her, some said to strangle her, while persuading Throckmorton that he was her best friend. Lethington tried to win her favour in her prison, but, having ‘no assurance from her,’ fled on a false report of her escape. Lethington fought against her at Langside, and Mary knew very well why, though he privately displayed the Casket Letters, he secretly intrigued for her at York. Even his final accession (1569) to her party, and his death in her cause, did not win her forgiveness.
She dated from Carberry Hill her certain knowledge of his guilt in the murder, which she always held in reserve for a favourable opportunity. But, as she neither was allowed to see the Casket Letters, nor to appear in person before the Peers, that opportunity never came.
To conclude this part of the inquiry: Mary’s attitude, as regards the Letters, was less that of conscious innocence, than of a player who has strong cards in her hand and awaits the chance of bringing out her trumps.