The Queen and Prince Philip wanted their youngest son Prince Edward to be bestowed the title of Duke of Edinburgh once Prince Charles becomes king. They reportedly assured him ahead of his marriage to Sophie Rhys-Jones in 1999.
Prince Charles inherited the title in April after his father's death, and once he succeeds Her Majesty the title will automatically revert back to the crown.
Doubts have emerged in recent days about the Earl of Wessex being granted the title once Charles becomes king, with one expert suggesting the Queen may need to "have a word" with her eldest to ensure her and Philip's will is respected.
Royal commentator Richard Kay was reported to have said: "My feeling is that if the Queen were to have a word in her son's ear, then Charles would fall into line and Edward will get the title."
The expert added: "He's doing so much of the monarchical duties, he's the head of the family effectively now, all the problems with Prince Harry, Prince Andrew uncertainty over his scandal. You'd have thought this wouldn't have mattered but these things matter to the royals - they take these titles incredibly seriously."
The Prince of Wales has become the de facto head of the family since Prince Philip's demise in April as he now is the most senior male member of the monarchy.
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