Mary Stuart, Queen of Scots, was one of history's romantically tragic figures. Devious, naive, often principled, beautiful and sexually voracious, this was a woman who had secured the Scottish throne and bolstered the position of the Catholic Church in Scotland. Her endless plotting, including a probable involvement in the murder of her husband Lord Darnley, eventually led to her flight from Scotland and imprisonment by her equally ambitious cousin and fellow queen, Elizabeth of England. And yet when Elizabeth ordered her unpredictable rival and kinswoman to be beheaded in 1587 she did so in resigned frustration rather than as an act of political wrath. Was the beheading of a cousin truly necessary? Did Mary, though churlish, petulant and often disloyal, deserve to forfeit the compassion of her cousin, a woman who had since childhood been her friend and playmate? Mary's fragile fate was to be born to supreme power whilst totally lacking in the political ability to deal with its responsibilities. Her story, which has inspired poets, playwrights and operatic composers of the centuries, is one of the most colourful and emotional tales of Western history, and is here told by a specialist of the 16th century.