The Queen’s grandson, Peter Phillips, and his wife Autumn have described their separation as sad but amicable, and “the best course of action for their two children and ongoing friendship”.
The couple are in the process of divorcing, and will share custody of their two daughters.
A spokesman for pair, who wed at St George’s Chapel in Windsor Castle in 2008, said the decision was taken after many months of discussion, and they informed the Queen and their families last year.
Canadian-born Autumn will not return to her home country, but will remain in Gloucestershire where they will co-parent nine-year-old Savannah and seven-year-old Isla.
The spokesman said: “They had reached the conclusion that this was the best course of action for their two children and ongoing friendship.
“The decision to divorce and share custody came about after many months of discussions and, although sad, is an amicable one.
“The couple’s first priority will remain the continued well-being and upbringing of their wonderful daughters, Savannah and Isla.
“Both families were naturally sad at the announcement, but fully supportive of Peter and Autumn in the joint decision to co parent their children.”
“Both Peter and Autumn have remained in Gloucestershire to bring up their two children where they have been settled for a number of years.”
The couple requested “privacy and compassion” for their children while the family continues to adapt to the changes.
Phillips, 42, son of Elizabeth’s daughter Princess Anne and 15th-in-line to the throne, and Autumn, 41, met in 2003 at the Montreal Grand Prix, when he worked for the Formula 1 racing team BMW Williams and she worked at the BMW hospitality suite.
They married at the queen’s Windsor Castle residence near London, the scene for a number of recent royal weddings including that of another of Elizabeth’s grandsons, Prince Harry to his American wife Meghan.
Phillips has no royal title and has tended to stay out of the limelight. He did, however, organise a giant street party in front of Buckingham Palace to celebrate the queen’s 90th birthday in 2016.
The Sun said the monarch, 93, would be very upset by the news, which comes on the back on a series of major setbacks for the royal family.
Harry and Meghan plunged the Windsors into crisis last month when they announced they wanted to cut back on official duties. That led to a deal which means they will retire as working royals to spend more time in Canada and the United States.
Meanwhile, the queen’s second son Prince Andrew also stepped down from public duties in November over his connections to sex scandals involving late U.S. financier Jeffrey Epstein.
“The queen must wonder what she has done to deserve this,” the Sun quoted an unnamed senior royal source as saying.
“Peter Phillips has always been a favourite of hers and Prince Philip and she will be crestfallen by this, especially on top of all the other bad news. It makes you wonder what’s going to happen next.”