With the flair for narrative and the meticulous research that readers have come to expect, in The Diamond Queen Andrew Marr turns his attention to the monarch - and to the monarchy, chronicling the Queen's pivotal role at the centre of the state, which is largely hidden from the public gaze, and making a strong case for the institution itself.

Arranged thematically, rather than chronologically, Marr dissects the Queen's political relationships, crucially those with her Prime Ministers; he examines her role as Head of the Commonwealth, and her deep commitment to that Commonwealth of nations; he looks at the drastic changes in the media since her accession in 1952 and how the monarchy - and the monarch - have had to change and adapt as a result. Indeed he argues that under her watchful eye, the monarchy has been thoroughly modernized and made as fit for purpose in the twenty-first century as it was when she came to the throne and a 'new Elizabethan age' was ushered in.