One of Prince Philip's long-time friends says the nation's longest-serving consort had just one complaint about the Queen during their 73-year marriage.
The Duke of Edinburgh shook his head in mock disbelief as he complained about the time his wife spent on the phone, said royal biographer Gyles Brandreth.
He also revealed what Philip, 99, really thought about Prince Harry and Meghan Markle's departure as senior royals and their interview with Oprah Winfrey.
In the wake of the the duke's death on Friday, tributes have been paid to the couple's unique relationship and Philip's dedication to the Queen and his supporting role.
The Royal Family shared a quote from the Queen on her 50th wedding anniversary in 1997, in which she called her husband "my strength and stay all these years".
When Philip retired from public life in 2017, he began to live out his days at his cottage, Wood Farm, on the Sandringham estate while the Queen stayed primarily at Buckingham Palace under a reduced workload.
They didn't see much of each other but would stay in touch by phone, the TV presenter and former Tory MP Mr Brandreth wrote in the Daily Mail.
But the amount of time the Queen had to spend on the phone - speaking to everyone from world leaders to her horse racing manager - apparently annoyed her husband.
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Mr Brandreth, 73, wrote: "The only complaint I ever heard Prince Philip make about the Queen was about the time she spent on the phone.
"'She never stops,' he said, shaking his head in mock disbelief."
Mr Brandreth also spoke of Philip's love of vehicles and driving, an activity he enjoyed into his late 90s, though he was involved in a serious crash near Sandringham in 2019.
The biographer wrote: "One of the police officers detailed to look after him told me that, regularly, he would hear the Prince, in his 90s, calling out to the Queen (and anyone else within earshot), 'Where are the f***ing car keys?'
"He went on with his carriage driving for as long as he could. He continued with his exercise routine as best he was able."
Mr Brandreth said Philip told him he watched TV "without much pleasure" and didn't bother to watch the Netflix series The Crown, which dramatised his and the Queen's life, because he had zero interest in "soap operas".
The duke carried on painting and reading books, especially anything on military history and biographies, in his final years, and would scan the obituaries in newspapers to see if anyone he knew had died.
Mr Brandreth said some people were "shocked" that the Queen and Philip would go weeks without seeing each other while he spent time on his own at Sandringham in Norfolk.
But the Queen understood that he wanted to be "left to his own devices" and "see out his days in his own way" after more than 70 years of duty.
The couple had spent much of the last year shielding together at Windsor Castle, where Philip died in his sleep two months before his 100th birthday.
The duke spent a month in London hospitals, where he underwent heart surgery and was treated for an infection, until he was discharged on March 16, the final time he was seen in public.
It is said that he refused to go back to hospital and was determined to die at home.