As Prince Harry marks his 40th birthday this Sunday, he’ll be surrounded by the family he’s built with wife Meghan.

The pair and their two young children are thought to be celebrating the milestone in California, their chosen home after stepping back from Royal duties. However, things could have been very different if Harry had heeded advice from advisors including his uncle, Earl Spencer, brother of the late Diana, Princess of Wales.

In his book, Revenge: Meghan, Harry and the War between the Windsors, Tom Bower alleges that Earl Spencer was asked to counsel Harry about his relationship with Meghan.

According to Bower, Earl Spencer and Diana’s sisters, Lady Sarah McCorquodale and Baroness Jane Fellowes, believed Meghan would find it difficult to adapt to the Royal Family.

The book details how by autumn 2017, Harry had introduced Meghan to Diana’s two sisters, Jane and Sarah, and her best friend Julia Samuel. Bower wrote: “Harry assumed that Diana’s family and friends would see a similarity between Diana and his fiancee. Both, he said, shared the same problems. He was disappointed.

“No one agreed that his vulnerable mother had anything in common with his girlfriend. More discomforting for him, they thought Meghan would not fit in with the Royal Family. Their unease was voiced by Charles Spencer, Diana’s brother. At William’s request, Spencer weighed in.

Princess Diana’s brother was not pleased (Image: AFP via Getty Images)

“Three times married, Spencer cautioned his nephew to reconsider his haste towards marriage. His advice provoked a bitter reaction. ‘This was going to be really hard,’ Harry would later reflect on establishing Meghan’s place in the family.”, reports the Mirror.

Tom hinted that Earl Spencer wasn’t alone in his skepticism about Harry and Meghan’s whirlwind romance. He revealed that Meghan’s ex-talent agent, Gina Nelthorpe-Cowne, warned the starlet she “wouldn’t be able to make any more movies” once she committed to Royal duties.

However, Meghan reportedly saw red over this, with Tom claiming she was seething with a “hard fury” at the notion.