Writing in her 2019 biography, Harry: Conversations with the Prince, Angela Levin explained why Harry may have changed for Meghan.
She said: “Harry has always worn his heart on his sleeve.
According to Angela, however, the changes in Prince Harry haven't all been positive.
“On many occasions he has also seemed to be a shadow of himself: miserable, tense, sulky and even emasculated. It’s hard to pinpoint exactly why, but perhaps all the changes Meghan has encouraged him to adopt have temporarily made him no longer feel quite himself," she wrote.
"He also seems to be less active. In 2018 he only fulfilled 193 royal engagements compared to 507 undertaken by Prince Charles.”
She said: “He is emotionally vulnerable and has no wish to contradict a charismatic and extremely determined wife.
“I have been told from an insider that both the Queen and Prince Charles are very worried about him.”
According to Angela, Prince Harry often stands in the shadow of his wife Meghan, who is a feminist and human rights campaigner.
Meghan once wrote on her online blog, The Tig: “My mother raised me to be a global citizen with eyes open to sometimes harsh realities.”
She even “unknowingly and somehow accidentally” an advocate for women’s rights when she was in her youth when she was enraged by a ‘sexist’ soap advert.
And she doesn't hold back, making sure she works for the causes she supports, as Angela added: “She wrote a protest letter to the soap powder manufacturers Procter and Gamble plus various prominent women, including Hillary Clinton, who was then First Lady."
“She got tremendous support, appeared on TV herself, and within a few months the commercial changed the word ‘women’ to ‘people’. It is something she remains proud of and often mentions,” Angela wrote.
However these are also all positive points, which no doubt Harry loves his wife for.
The couple, who welcomed their first child, Archie Harrison, on May 6, have stood by each other during testing times this year.
With rumours swirling that the pair will be looking to buy a home in California when they visit Meghan's mum - Doria Ragland - over the Thanksgiving holiday, a source has revealed that following their Royal tour of South Africa Meghan and Harry have decided to take more quality time for themselves.
"It hasn’t been an easy year for the pair, with all the drama surrounding them, and having to look after a newborn," the insider dished to Us Weekly.
"After the birth, they were absolutely exhausted."
The Duke and Duchess of Sussex are famously going against the wishes of Buckingham Palace and suing the Mail on Sunday for printing personal letters from Meghan to her father, that were shared to the publication by Thomas Markle himself.
The source continues: "There were times they’d bicker over the smallest things because they were so tired. But now that Archie’s sleeping through the night, there’s less strain on the marriage. They can finally enjoy some ‘couple time’ in the evening and feel more rested."