And although Queen Elizabeth is the monarch, behind closed doors Paul says Phillip is the head of the family, so any change in circumstances will be very hard on her.
Paul describes Prince Phillip as a 'man not to be messed with' who does not 'suffer fools gladly' but also has a kind and gentle side.
Now moving into 2020, the Queen will remain at her husband’s side at Sandringham until February when she will return to her royal duties.
Paul says Elizabeth is leaning on her inner strength and counting her blessings. 'She’s had Prince Phillip beside her for most of her life and for that she is very grateful.'
'I think Grandpa is incredible,' Princess Eugenie said during the documentary Our Queen at Ninety.
Actor Matt Smith, who played Philip in the first two seasons of The Crown, recalled how Prince William had described his grandfather as 'a legend' when they met.
Prince Harry paid very obvious tribute to Philip by adding his surname, Mountbatten, to baby son Archie’s full name.
Despite stepping away from royal duties in 2017, the duke has been renowned for his humour. In 2000, Prince Philip revealed he had 'no desire whatsoever' to live to his 100th year. Only a few years earlier, in 1997, the Queen paid tribute to her husband, the man who has always been her rock.
'He has, quite simply, been my strength and stay all these years, and I and his whole family, in this and many other countries, owe him a debt greater than he would ever claim or we shall ever know.'