On Elizabeth I’s death on 24 March 1603, King James VI and I united the crowns of Scotland and England, creating what he loved to call his ‘empire of Great Britain’. Two years later, Sir Francis Bacon wrote to Lord Chancellor Ellesmere, urging him to commission a new and ‘worthier’ Anglo-Scottish history to memorialise this event and so liberate Scotland from the ‘partiality and obliquity’ of its most recent historian, George Buchanan, James’s hated former tutor and the chief traducer of his mother. For 400 years Bacon’s appeal fell on deaf ears, but in Crown of Thistles, Linda Porter has finally responded, crafting the national histories into a genuinely ‘British’ interpretation of the long century from the 1450s until Mary Stuart’s flight across the Solway Firth to exile in England in 1568.

The enterprise is fraught with hazards. In particular, Porter’s decision to end the narrative in 1568, covering the remaining 19 years before Mary’s execution in the flimsiest of epilogues, begs an important question. Porter assumes that Mary’s captivity in England made the Union of the Crowns inevitable, but her exile