By drawing upon recent scholarship, original manuscript materials, and previously unpublished sources, this new biography presents an analytical narrative of King James VI & I’s life from his birth in 1566 to his accession to the throne of England and Ireland in 1603. The only son of Mary Stuart and heir (apparent but not uncontested) to Elizabeth I, James VI of Scotland was, from the moment of his birth, a focal point of countervailing hopes and fears for the confessional and dynastic future of the kingdoms of the British Isles. This study examines material from across the UK and beyond, as well as the newly deciphered letters of Mary, Queen of Scots, to reveal James as a highly capable, resourceful, deeply provocative and ruthless political actor. Analysis of James’s own writings is integrated within the narrative, providing fresh insights into the king’s inventive tactical engagement in the politics of publicity. Through a chronological approach, the events of his life are linked to wider issues associated with the early modern court, government, religion, and political and ideological conflict. James VI, Britannic Prince is of interest to all scholars of Scottish and British history in the late sixteenth and early seventeenth centuries.