‘I’m coming.’

Susan trots importantly along beside Elizabeth as she walks along the interminable palace corridors towards the room overlooking the forecourt where they always gather before appearances on the balcony.

This is the official day of celebration, although the jubilation has been going on since Churchill’s announcement the day before. All night, fireworks streaked across the sky and the crowds surged through the streets.

The sense of relief is profound after six long years of war. They all feel it, a slackening of tension, a great unloosening, a collective exhalation, as if the country has been hunched in on itself, holding its breath and is now letting it go in an outpouring of emotion.

When she first heard the news, Elizabeth’s heart had pounded so hard that she had had to press a hand to her chest to stop it breaking through her ribs. At last, at last! For a brief moment the relief had been so intense that it was painful.

Now poor, battered London has erupted in celebration. People who have lost everything but their lives are converging on the palace, clambering over the Victoria Monument and pressing up against the gates.

The room that overlooks the forecourt is full of people. Everybody is smiling and chatting and the noise both inside and out is deafening. Elizabeth is delighted to see her father’s thin face relaxed for once. It lights up when he sees her.

‘There you are,’ he says as the chants of ‘We want the King!’ grow ever more insistent. ‘Ready?’

Elizabeth nods, and waits for him to extricate the Queen from a conversation with her favourite brother, David Bowes-Lyon, and send his equerry, Group Captain Townsend, to gather up Margaret.

‘It’s worse than trying to herd the corgis,’ the King pretends to grumble.

At last the four of them are all together. The King glances at the Queen, who smiles back at him in a wordless conversation. There is a bond between them that Elizabeth envies. She would like to be married to man who would look at her the way her father looks at her mother.

Philip is not like her father.

‘Out we go,’ the King says. ‘Just be careful, though. The balcony is a bit shaky after that bomb.’

He and the Queen step out first and then Elizabeth and Margaret follow to stand on either side of their parents, Susan having been firmly commanded to stay inside. The cheer that goes up startles the pigeons pecking around the forecourt or hunched on the rooftops, oblivious to the drama. They flutter up and circle indignantly before returning, ruffled, to their perches. The sound hits the royal family like a great wave, a buffet of air that almost makes Elizabeth stagger back, such is its force. Overwhelmed, she lets out a shaky breath and smiles and lifts her hand to wave as her heart swells.

The balcony is draped in crimson and gold; beyond, the seething mass of people stretches far back along the Mall. What would it be like to be down there? she wonders. To be part of the crowd, looking up instead of looking down? Why are you cheering us? Elizabeth wants to call down to them. You are the ones who have stuck it out and survived. You are the ones who have taken every blow. I have just learnt to change a tyre.