At lunchtime on Thursday, the bells of Westminster Abbey rang out in the wintry sunshine, filling the blue sky above the Houses of Parliament and the River Thames with joyful sound. It was a deeply British moment: the nation's most famous church celebrating the 38th birthday of Kate Middleton, the wife of Prince William, who will one day become King.
But amid the pageantry, the royal family was reeling from another crisis. Hours earlier, William's younger brother, Prince Harry and his wife Meghan Markle, had dropped a bombshell, announcing -- without warning -- they are quitting their roles as senior royals to spend more time in North America. They want to become financially independent and "carve out" a "progressive new role."
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For a country obsessed with its history of kings and queens, it was a shocking and confusing development. Harry is the most famous member of the royal family and second-most popular after his grandmother, Queen Elizabeth II, according to YouGov research.
His exit raises questions over the place of the monarchy in British public life and its ability to keep pace with a country undergoing the revolutionary changes unleashed by Brexit.
Since the UK voted to leave the European Union in 2016, its politics have been pitched into disarray, with angry adversaries lining up to attack each other from both sides of the toxic Brexit debate.
As Parliament collapsed into chaos and the governments of David Cameron and Theresa May fell apart, the monarchy provided a rare point of stability, as well as a welcome distraction. In May 2018, the nation delighted in the marriage of Harry to Meghan, and then a year later the birth of their son, Archie.
The entire British establishment is geared toward protecting the monarchy from political controversy and keeping the queen above the fray. Any misjudgment could set in train events that would threaten its very existence.
But the royal family matters deeply for British politics, too. As head of state, the queen occupies a vital part of the constitution, signing bills into law, convening Parliament and appointing prime ministers. She is also Britain's most effective diplomat, receiving visits from dignitaries to her palaces and castles and undertaking overseas trips to strengthen relations with allies.
When the UK ends its 45-year alliance with the countries of the EU on Jan. 31, it will need its royals to work overtime to win new friends. Prime Minister Boris Johnson has made clear he will open trade negotiations with other countries as soon Brexit is delivered, including with the U.S.
President Donald Trump has enjoyed several tours to Britain, including a full state visit last June when he dined with the queen at Buckingham Palace.
The royals have significant economic influence, too. An estimated 2.7 million visitors a year come to Buckingham Palace and Windsor Castle, the queen's residences, while a 2017 report by Brand Finance valued the monarchy's contribution to the economy at 1.8 billion pounds ($2.4 billion) a year.
"The young royals are an extension of British soft power, acting as one of the biggest pull factors for tourists visiting this country," Brand Finance CEO David Haigh said.
Johnson will also need a stable monarchy to keep the U.K. together. Brexit tensions have revived the movement toward Scottish independence. While last month's general election brought some parliamentary stability in London, it widened the political divide between England and Scotland.
As former Prime Minister David Cameron once infamously revealed, the queen herself had been preoccupied with the first referendum on Scotland's independence in 2014 and "purred" on the phone when he told her the country had voted to remain part of the U.K.
When her reign finally ends, the question will be whether the rest of the family can retain the levels of support she enjoyed in her time as a constant presence in the nation's affairs.
As a young prince, who won public affection and sympathy after his mother Princess Diana died when he was a child, Harry could have helped.
In his wilder youth, he was frequently in the headlines for the wrong reasons. He was photographed wearing a Nazi uniform, and on another occasion naked pictures leaked of him playing strip billiards in a Las Vegas hotel room in 2012.
Yet as a former soldier who served in Afghanistan, he's hugely popular and has a natural touch with the public that's been likened to that of his mother.
In the short term, his highly contentious decision looks unlikely to win Prince Harry the peace he craves. The bitter row with other members of the royal family is set to include a wrangle over how far he and his wife should get taxpayer-funded security, a bill likely to rise if they spend more time overseas. Media attention is now more intense than ever.
For the royal family, the loss of such a modern prince who can connect with younger generations is a blow to the institution's image ahead of some momentous tests.
Queen Elizabeth, 93, has been on the throne for 67 years, while her husband, Prince Philip, has struggled with his own poor health in recent years.
The queen is loved by the public, described by fans as "admirable, hard working, respected, dignified and dedicated."
But at 71, her heir Prince Charles is already facing a battle to win over the support of the public. He ranks seventh on the YouGov list, while his second wife, Camilla, is 10th. Just 30% of respondents gave her a positive rating.
In November, Charles's brother Prince Andrew was forced to announce he will be stepping back from public life after he became embroiled in the Jeffrey Epstein pedophile scandal.
The government has secret plans which will be put into action in the days after the queen dies. A report in the Guardian newspaper 2017 explained the nature of officials' concerns: "The queen is approaching the end of her reign at a time of maximum disquiet about Britain's place in the world," it said.
For senior members of the royal family, the bells will continue to ring out to wish them a happy birthday. As Prince Harry turns his back on all the pomp, the risk for the monarchy and the stability of the British state is the public might follow his lead.