During his brief political career, Archibald Campbell, 5th earl of Argyll (1530-73) played a crucial role in the mid-century upheavals in Scottish and British politics. This definitive study on Argyll is a major contribution to Scottish political history, and a significant new contribution to the history of the reign of Mary, Queen of Scots. The study of his career changes significantly the axis of mid-Tudor studies as well as the study of the dynamics of Scottish history. Important European contexts and resonances are also explored.