Prince Philip's blunt verdict on Kate Middleton when she came into William's life showed he was a shrewd judge of character
The late Duke of Edinburgh was reportedly 'relieved' that she had this personality type as a potential future Queen
Prince Philip was known for getting straight to the point and he didn't hold back when it came to his first impression of the Princess of Wales either. According to the late Duke of Edinburgh's biographer and friend Gyles Brandreth, he was "relieved" when Kate came into his grandson's life as a "potential bride" and shared his short verdict.
"The Duke of Edinburgh was, he told me, 'relieved to find her such a level-headed girl', Brandreth claimed in Philip: The Final Portrait. This was high praise from the formidable Prince, especially because he had apparently been "worried" about the late Princess Diana's reaction to popularity.
The biographer alleged, "One of the things that saddened - and worried - the Queen and Prince Philip about Diana, Princess of Wales, was not that she was popular, but that she allowed her popularity to go to her head."
Therefore Prince Philip's description of Kate as "level-headed" could be seen as an even bigger endorsement of her as Prince William's then-girlfriend and possible future Queen. His opinion was also massively respected by the rest of the Royal Family and counted for a lot.
"Different generations had leaned on him for personal guidance and his acceptance, or rejection, of others brought into the fold by marriage was seen as a moral compass by those navigating life within the confines of the monarchy," writes royal expert Russell Myers in William & Catherine.
The Princess of Wales clearly wholeheartedly accepted by the Duke of Edinburgh, though he also reportedly "warned" William against proposing too quickly. Myers suggests that he'd been influenced by seeing the marriages of three of his four children - King Charles, Princess Anne and Andrew - ending in separation and divorce.
He apparently "backed him in taking his time while he considered whether he had absolute confidence in his relationship with Catherine before making the biggest decision of his life."
In 2011 William and Kate tied the knot and she went on to forge a close relationship with her grandfather-in-law over the years. He's said to have sympathised with her as an outsider marrying into The Firm and one of his former aides told Myers that Philip was very "fond" of the Princess.
"[He] thought she was the best thing to happen to the Royal Family since he came along," the aide added with a smile.
It was also the Duke of Edinburgh who is understood to have given the future Queen a very valuable bit of advice about handling the press and photographers. As a "level-headed" person, Kate has never let this go to her head and according to Brandreth, Philip thought, "If you believe the attention is for you personally, you're going to end up in trouble.
"The attention is for your role, what you do, what you're supporting. It isn't for you as an individual. You are not a celebrity. You are representing the Royal Family. That's all."
As Britain's longest-serving royal consort Prince Philip knew what he was talking about and it's perhaps why you rarely see the Princess of Wales looking directly at the photographers or seeming to be even aware they're there.
