(CNN) Queen Elizabeth's eldest grandson, Peter Phillips, and his wife Autumn have decided to divorce, a spokesman for the couple has revealed in a statement.

ASCOT, ENGLAND - JUNE 22: Peter Phillips and Autumn Phillips attends day five of Royal Ascot at Ascot Racecourse on June 22, 2019 in Ascot, England. (Photo by Chris Jackson/Getty Images)

The royal couple jointly agreed to separate after informing the Queen and family members last year, their spokesman Gerard Franklin said on Tuesday.

(L-R) The Duchess Of Cornwall, Duchess of Cambridge, Duchess of Sussex, Duke of Sussex, Peter Phillips, Autumn Phillips and their children Isla and Savannah Phillips on the balcony of Buckingham Palace in 2018.

"They had reached the conclusion that this was the best course of action for their two children and ongoing friendship," the statement read. "The decision to divorce and share custody came about after many months of discussions and although sad, is an amicable one."

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The couple said their first priority would remain "the continued well-being and upbringing of their wonderful daughters," Savannah, nine, and Isla, seven.

"Both families were naturally sad at the announcement, but fully supportive of Peter and Autumn in the joint decision to co-parent their children," the statement continued.

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