– In a year of gut punches to Britain's royal family, Prince Harry and his wife, Meghan, delivered a jarring blow of their own Wednesday, announcing that they would "step back" from their official duties.

It was an extraordinary retreat by the popular prince and his wife, who had grown increasingly isolated within the House of Windsor since their wedding in 2018.

The Duke and Duchess of Sussex, as they are also known, said they planned to divide their time between Britain and North America and would "work to become financially independent."

"After many months of reflection and internal discussions, we have chosen to make a transition this year to carve out a progressive new role within this institution," the couple said in a post on their Instagram account.

While the language in the statement was mild and upbeat, the change is momentous. Although he is sixth in the line of succession to Queen Elizabeth, Harry has exerted an outsize hold on the public imagination ever since his days as the mischievous, ginger-haired younger son of Prince Charles and Princess Diana.

For the duke and duchess to forsake Britain and relinquish their royal duties, even for part of the year, will be a jolt to one of the nation's most immutable institutions. It continues the convention-defying ways of Harry, who enthralled millions and angered others when he decided to marry a biracial American actress.

Buckingham Palace issued a two-line statement Wednesday evening, suggesting that the announcement had caught the royal family off guard, if not blindsided it. "Discussions with the Duke and Duchess of Sussex are at an early stage," the statement said. "We understand their desire to take a different approach, but these are complicated issues that will take time to work through."

Among those issues, one royal watcher said, was how a partial self-exile would work. Other members of the family have been exiled because of divorce, abdication or their own behavior. But no one has attempted the half-in, half-out arrangement that Harry and his wife appear to be pursuing.

It raises questions about how they would support themselves, since British taxpayers now fund their security, among many other expenses.

Harry is the second prominent royal to step back from his official duties in just three months. Prince Andrew said in November that he would retire from public life after a calamitous interview with the BBC reignited accusations that he was involved in sex trafficking with disgraced financier Jeffrey Epstein.

Wednesday's announcement came amid persistent rumors of tensions between Harry and Meghan and his brother, Prince William, and his wife, Kate. In October, during a trip to South Africa, the Sussexes opened up to TV interviewer Tom Bradby. The duchess said she was struggling with being a royal and a new mother. Harry kindled rumors of a rift by saying that he and William were on "different paths."

On Wednesday, the duke and duchess said they would continue "to fully support Her Majesty the Queen" and charities with which they are affiliated. But they said they wanted to give their 8-month-old son, Prince Archie, "geographic balance" in his upbringing. Spending part of the year outside Britain, they said, would provide their family with "the space to focus on the next chapter, including the launch of our new charitable entity."

The couple did not say where in North America they planned to live, but royal watchers said they expected it to be Canada. The couple spent several weeks during the holidays at a house in Vancouver, and the duchess, previously known as Meghan Markle, lived for several years in Toronto, where her television series, "Suits," was filmed.

"It's an extraordinary announcement," said Penny Junor, a royal biographer. "We will miss them, but I don't think it will be all that damaging to the royal family."