Tom Bower's earth-shattering new book 'Revenge: Meghan, Harry and the War between the Windsors' claims to offer a behind the scenes insight into Prince Harry and Meghan's relationship with other members of the Royal Family.
The author reportedly spoke to 80 people who personally know the couple to reveal what really happened at some of the most talked about royal events of recent times.
One appearance that will be remembered thanks to visible family tensions and icy greetings was the annual Commonwealth Day Service at Westminster Abbey in 2020.
The Duke and Duchess of Sussex attended the event as it marked their final engagement as senior royals along with the likes of The Queen, The Prince of Wales and The Duke and Duchess of Cambridge.
Bower's explosive book addresses the service and explains how a "monumental argument" took place after "Palace officials … decided to publicly humiliate [Harry and Meghan]".
Bower wrote: "Reality hit two days later, on 9th March. A monumental argument blew up after Harry was told that he and Meghan could not join the family’s procession through Westminster Abbey for the annual Commonwealth Day Service.
"Although the order of service listed Harry and Meghan walking behind the Queen, Palace officials had revised their decision. Suspicious about the Sussexes they decided to publicly humiliate them.
"Harry was told that having stepped down from royal duties, he and Meghan would sit and wait with the congregation. The prospect of the televised image of their isolation in the Abbey appalled them.
"By then they were keenly aware of Kate and William’s antagonism. William had not offered a brotherly welcome and Kate was outright distant towards her sister-in-law.
"Eventually, to end the dispute, William and Kate agreed they too would wait with Harry and Meghan. As the members of the Royal Family filed into the Abbey, the frayed relationships could not be concealed.
"Kate had blanked the Sussexes and William’s greeting was cold. Harry looked strained. Meghan’s face showed bemusement."
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Further explosive claims from Bower's book involve the infamous row between Meghan and The Duchess of Cambridge over the bridesmaid dresses at her wedding to Prince Harry in 2018.
The author claims that Kate was already irritated with Meghan over complaints that she was allegedly bullying her staff - accusations she has always strongly denied.
Bower explains that Kate was exhausted in the run up to the wedding as she had just given birth to Prince Louis. He claims that she was too tired to "cope with a disagreement about whether the bridesmaids should wear tights."
While this point of contention was known, Tom Bower writes that the pair had a second argument as Kate reportedly thought Princess Charlotte's dress was too short and did not fit.
The author says: "Kate burst into tears. Kirstie Allsopp, a friend of Camilla, would later confirm that Kate was reduced to tears by Meghan bullying her staff.
"After leaving that unhappy scene Kate decided to make amends. She crossed the Kensington Palace corridor and presented Meghan with a bunch of flowers. Kate also told Meghan not to speak rudely to her staff. 'That’s unacceptable.’
"What followed can never be irrefutably established. In Kate’s version, Meghan slammed the door in her face and threw the flowers in a dustbin.
"Meghan would tell Oprah Winfrey that the tears were shed by her, not Kate, and the flowers were an apology. 'I think that’s where everything changed,’ Meghan rightly said."
The royal family have declined to comment on the contents of Bower's book.
