The girls spent the day looking down the stairwell at the comings and goings of the prime minister and his ministers, and then rushing to the windows to stare at the thousands of people gathered outside. When a letter was delivered addressed to Her Majesty the Queen, Elizabeth turned to Lady Cynthia Asquith. ‘ “That’s Mummy now,” she said, with a tremor in her awestruck voice.’

Whatever awe she felt was offset by her inherent composure and her remarkable sense of responsibility. She was not worldly and has not become so. It was never intended that she should. The practice of keeping her emotions to herself in public acquired the force of habit in private. She does not like being touched. She raises her voice rarely; anger and temperament have no part to play in this lifetime’s exercise in self-control. Instead, she shows her displeasure by icy silence. If that makes her incomplete as a person – and there is an element of the child in her inability to address the sometimes-wayward behaviour of her own family – there is also a regality about her which is both reassuring and intimidating. The aura of majesty comes naturally to her. It was as if she always knew she was destined to be Queen and set about from the earliest age acquiring the necessary skills, always trying hard to do ‘what she felt was expected of her’.

She did not join Margaret in those practical jokes that are such a tradition in the royal family (as long ago as 1860, Lord Clarendon was saying that he never told them his best jokes because pretending to pinch his finger in the door amused them more). When Margaret hid the gardener’s rake or threatened to sound the bell at Windsor which brought out the guard, Elizabeth would hide with embarrassment. Order always had to be maintained. She was, said Crawfie, ‘neat and methodical beyond words. She would sometimes get up in the middle of the night to make sure her shoes were neatly stowed.’

Self-control was essential. At the Coronation of their father in Westminster Abbey, she said of her little sister, ‘I do hope she won’t disgrace us all by falling asleep in the middle.’ And when their parents set sail for the propaganda tour of Canada and the United States just before the outbreak of the Second World War, and Margaret told her that she had her handkerchief ready, Elizabeth sternly warned her, ‘To wave, not to cry.’