What's the key to Queen Elizabeth's heart?
Prince Philip, who turns 95 on Friday, said the secret behind his long-lasting marriage to the Queen is the fact that he makes her laugh, according to royal biographer Gyles Brandreth.
Brandreth, who was given "privileged access" to the Queen and Philip for his 2004 book, Portrait of a Marriage, shared some key moments of his conversations with the royals with the Radio Times, including praise for the prince for being the "power behind the throne."
"If we regard the Queen's record-breaking reign as a success – and I think most of us do – Prince Philip is the co-author of that success. The Queen wears the crown, but her husband wears the trousers. He is the power behind the throne – shrewd, steadfast, never-failingly supportive," he shared.
And despite their closeness, the royal couple won't ever be seen holding hands in public due to the "stoic values" of their generation, Brandreth revealed.
He also revealed that Philip admitted he is more of a "pragmatist," while his son Prince Charles is more of a "romantic."
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"I once asked Prince Philip about the reported differences between him and his eldest son, Prince Charles," Brandreth wrote. "He acknowledged 'one great difference' between them. 'He's a romantic,' he said, 'and I'm a pragmatist – that means we do see things differently.' He paused before adding, with a shrug, 'And because I don't see things as a romantic would, I'm unfeeling.'"
While Philip may not be a self-proclaimed romantic, that doesn't mean he can't still sweep his wife off her feet every now and then.
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The royal couple, who wed 68 years ago, are also longtime music lovers, as revealed by Cousin Lady Elizabeth Anson in BBC Radio Two's Our Queen: 90 Musical Years
"We did a lot of singing at Kensington Palace. Nobody thought it was odd after dinner if we put on a record and all sang "Doing the Lambeth Walk," so music has always been part of her life. The Queen is a fantastic dancer. She's got great rhythm," she shared.
"Her parents loved singing and passed it on. The Duke of Edinburgh and the rest of the family join in."