This paper explores aspects of Anglo-Scottish relations in Elizabeth's reign with particular emphasis on the idea of dynastic union and the creation of a Protestant British kingdom. It begins by examining the legacy of pre-Elizabethan ideas of Britain and the extent to which Elizabeth and her government sought to realise the vision of a Protestant and imperial British kingdom first articulated in the late 1540s. It then focuses on the issues arising from the deposition of Mary Queen of Scots and her long captivity in England. The dynastic implications of Mary's execution in 1587 are highlighted and it is argued that Elizabeth's policy towards James VI and Scotland betrays little or no interest in developing a truly British agenda.