Queen Elizabeth knew Prince Harry was quitting royal life when he "took the dogs".
The 95-year-old monarch was asked by one well-meaning visitor whether the Duke and Duchess of Sussex might one day return to life as working royals - but the Queen insisted she had no doubts about their long-term plans, after they quit the UK for North America.
Asked if the couple might be having second thoughts about their decision, the monarch is reported to have replied: "Of course not. They took the dogs."
The duke and duchess announced in 2020 that they would be stepping back as "senior" royals.
However, Harry - who has Archie, two, and Lilibet, nine months, with the duchess - has retained a close relationship with his grandmother.
In Robert Hardman's 'Queen Of Our Times: The Life Of Elizabeth II' - which has been previewed in the Daily Mail newspaper - a senior aide said: "Harry adores her. She is the one who has kept the relationship going.
"He talks to her a lot, not unlike the way Prince Charles used to turn to the Queen Mother."
Last year, meanwhile, a Buckingham Palace spokesperson confirmed that the duke and duchess will not return as working members of the royal family.
The announcement was made after conversations between Harry and various members of his family.
A statement from Buckingham Palace said: "The Queen has written confirming that in stepping away from the work of the royal family it is not possible to continue with the responsibilities and duties that come with a life of public service.
"While all are saddened by their decision, the duke and duchess remain much loved members of the family."
Meanwhile, a spokesperson for the duke and duchess confirmed that they "remain committed to their duty and service to the UK and around the world".
They added: "We can all live a life of service. Service is universal."
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