‘No, I don’t.’ The sleet has eased at last and Elizabeth knuckles the wet from her cheeks. ‘I’ve never left the country. Balmoral is the furthest I’ve been.’

Philip is taken aback. He knew their experiences have been different, but not quite how different. ‘Oh … I suppose not,’ he says. He might envy Elizabeth her family, but how stultifyingly decorous and boring her childhood must have been, shuttling between Windsor, Buckingham Palace, Balmoral, and Sandringham, always surrounded by deferential courtiers.

‘So what are they like, these places?’ she asks.

‘Huge,’ says Philip briefly. ‘Most of them would make Buckingham Palace look cosy.’

‘Really?’ Elizabeth laughs in disbelief. ‘We always used to joke that you need a bicycle to get around BP.’

‘Wolfsgarten is the same. Some of the palaces are pretty dilapidated, too. I used to go and stay with my cousin Helen because Michael, her son, is more my age, and we had lots of good times there. He became King of Romania when he was five, though of course that didn’t mean much to us then. He was just a playmate. They had a crumbling palace near Bucharest but when it was very hot in the summer we used to like going up to Peles Castle at Sinaia in the Carpathian Mountains. It’s like something out of a fairy story, all turrets and towers and courtyards. Michael’s grandmother told the most marvellous stories in her bedroom. I always called her Aunt Missie, and if we were naughty, we weren’t allowed to go and say goodnight to her and hear a story. It was the worst punishment!’

He smiles at the memory and then breaks off, realising he has been running on. ‘Sorry. There’s nothing worse than someone rabbiting on about people and places you don’t know.’

‘I like hearing about your childhood,’ Elizabeth says. ‘It’s so different from mine. Go on. Where else did you go?’

‘Well, my sisters and I spent a few holidays near Le Touquet when I was younger with the Foufounis family. Like mine, they’re Greek émigrés and I was great friends with their children, Ria, Ianni and Hélène. They had a terrifying Scottish nanny they called Aunty.’ He smiles reminiscently. ‘Ianni and I used to get into all kinds of trouble.’

His memories of Berck Plage are muddled now, he finds. Dusty tracks. Sand between his toes. The weight of Madame Foufounis’s Persian rug on his shoulder when he and Ianni had the grand idea of pretending to be carpet salesmen like the Arabs on the beach. Poor Ria, up to her hips in plaster. The sinking feeling that followed the smash of a vase, knowing Aunty was rolling up her sleeves to deliver a sound spanking. Philip preferred his spankings from Nanny Roose, who was firm but fair.

‘And then there was Panker, the Hesses’s summer house on the Baltic Coast. There were always lots of us there too, a mass of children running around. We spent all day on the beach. I just remember miles of white sand and glittering water and a huge, windy sky and this marvellous light …’