THREATENED with the English rack, John Leslie allegedly exclaimed to his interrogator Thomas Wilson that not only was Mary, Queen of Scots involved in the murder of her husband Darnley, but she had also poisoned her first husband Francis and then brought Bothwell ‘to the Fylde to be murdered’. In response, one critic has noted even-handedly that the bishop was ‘subtle and resourceful but not of the stuff of which martyrs are made’. Nevertheless, Leslie's desperate outburst – perhaps excusable under the emotional duress of torture – is completely at odds with our sense of his allegiance to Mary, and so it should be. For all material evidence points to Leslie's sincere and unflagging commitment to the cause of his queen. His literary efforts to resuscitate Mary's reputation and political career, spread over some 19 years, ensured that his name would be irrevocably associated with the defence of Mary. So inescapable is this connection, in fact, that referring to Leslie as Mary's arch-defender has become easy shorthand, often masking a limited understanding of the bishop's methods and principal concerns. This has had the unfortunate effect of forestalling any detailed study of Leslie's works, as well as leading us to assume that Leslie sought primarily to recover Mary's damaged reputation. He was concerned about that, of course. But more than 450 years of speculation about Mary's character, fuelled in part by the wickedly clever propaganda of Robert Sempill and George Buchanan, among others, has skewed our perception of the debate in which Leslie was engaged, for Leslie's project was deeply invested with the political possibility of Mary's restoration. Certainly, he defended her against charges of immorality, but one of his strategies in doing so was to shift the terms of the Marian debate by breathing new life into the Elizabethan succession issue. Not only does Leslie envision a recovery of Mary's political career, but he also uses her claim to the English throne – as Elizabeth's legitimate heir – to constitute her very defence. Perhaps even more startlingly, in addressing the charges against her, he uses her gender to strengthen his political argument: her femininity is a warrant both for her innocence and her place in the English succession. This chapter aims to elucidate Leslie's principal concerns and his methods for the design of Mary's defence.