'You don't mess with Gran': the private life of Elizabeth II

The Queen's serene, controlled persona hid a sharp temper, quick wit and strong belief in family and religion

You don't mess with Gran," Prince Harry told a television interviewer in 2012, the year of his grandmother's diamond jubilee. In that one sentence he conjured up the backbone that had carried Queen Elizabeth II through one of the longest reigns in British history, presiding over a family dynasty which had its difficult moments but by the end of her time on the throne had established itself in the public affection. In terms of length of reign and longevity, she had equalled even her great-great-grandmother, Queen Victoria, whose own diamond jubilee in 1897 had represented the last great blaze of imperial splendour.

How had Elizabeth transformed herself from the shy girl who was only 10 when she became heir presumptive after her uncle Edward VIII had abdicated on 10 December 1936, making way for her nervous, stammering father, King George VI? Lillibet", as she was known in the family, had been brought up with her younger sister, Margaret Rose, in a typical upper-class nursery on the top floor of a five-storey Mayfair house, No 145 Piccadilly (destroyed by a bomb in the second world war).