Meghan Markle should have confided in Prince Philip before stepping down from the Royal Family because he also struggled to fit in at first, it has been claimed.
The Duke of Edinburgh suffered a torrid time after he first began dating the Queen and would have happily counselled the former Hollywood star, royal author Ian Lloyd said.
In his new book, The Duke: 100 Chapters in the Life of Prince Philip, the writer says the Duke would have been disappointed Prince Harry and Meghan stepped down last year.
"If Meghan had consulted him about the problems she had in fitting in, I have no doubt he would have told her of his own," Mr Lloyd said, reports the Telegraph.
"He would have counselled her. But he would also have said, 'Put your head down and get on with it'."
Mr Lloyd said Philip has a "profound respect" for The Firm and to him "duty is everything", particularly over personal fulfilment.
He goes on to say Harry and his grandfather have always been close but the latter would see the Sussexes' decision to move abroad as a "dereliction of duty".
The book is the result of interviews with multiple Palace insiders and paints a profile of Philip as someone who was treated as an outsider when he first dipped his toes into British royal life.
The Duke came from a particularly adverse background in which he found himself "virtually an orphan" from age nine after his mum had a breakdown in 1930 and his dad fled to France with a mistress, says Mr Lloyd.
He had been born into the Greek and Danish royal families and suffered a similar amount of xenophobia from some corners of Britain at first - much like Meghan, the book claims.
Unlike the Duchess, however, Mr Lloyd says Philip has always refused to pursue criticism and speculation in public, including rumours of alleged affairs which dogged him for years.
"He knew it would only fan the flames," according to the author, who believes the Duke would have warned Meghan against pursuing her successful claim for the publication of extracts from a private letter.
Mr Lloyd said aristocratic friends of Her Majesty's parents King George VI and Queen Elizabeth made "mischief in the background" when Philip first came on the scene.
He writes: "He was far poorer than them and had this awful time fitting in. They really hated him. He was seen with great suspicion, not just by the courtiers but by the King and Queen's friends, who despised him."
More pressure was put on his shoulders when just five years after marrying the then Princess Elizabeth, she became Queen in 1952 and he had to carve out a substantial public role for himself, though always on the periphery.
Mr Lloyd said, like Harry: "He's never been head of his own family and he's never had a starring role. I think he found it hard - but he did try to adjust."
Philip's 100th birthday is fast approaching on June 10 and the author predicts it will likely be a low key lunch with family, followed by a group photo and possible church service.
Harry is expected to return to the UK for the celebrations, though Meghan and son Archie are likely to stay in the US.