Prince Charles has tested positive for coronavirus and is self-isolating at home with "mild symptoms," says Clarence House.
The Prince of Wales, 71, has had a "high number of engagements" in recent weeks and it is "not possible to ascertain" where he caught the virus, his spokesman said.
Charles is the first Royal Family member to be diagnosed with Covid-19, and he falls within one of the highest risk categories given his age.
Clarence House said he "otherwise remains in good health" and has been working from home over the last few days despite catching the potentially deadly illness.
Camilla, the Duchess of Cornwall, has tested negative for coronavirus and is self-isolating at Birkhall in Scotland along with Charles, although they are apart from each other at the residence.
The tests were carried out by the NHS in Aberdeenshire.
A Clarence House spokesman said: "He has been displaying mild symptoms but otherwise remains in good health and has been working from home throughout the last few days as usual.
"The Duchess of Cornwall has also been tested but does not have the virus.
"In accordance with Government and medical advice, the Prince and the Duchess are now self-isolating at home in Scotland.
"The tests were carried out by the NHS in Aberdeenshire where they met the criteria required for testing.
"It is not possible to ascertain from whom the Prince caught the virus owing to the high number of engagements he carried out in his public role during recent weeks."
Charles and Camilla are self-isolating individually at Birkhall in Scotland, a source said.
The prince travelled to Birkhall on Sunday and he was tested on Monday.
Charles' recent engagements include an investiture ceremony at Buckingham Palace, where he wasn't shaking hands with guests, and a dinner at Mansion House in London in aid of the bushfire relief effort in Australia.
Prince Albert of Monaco tested positive for coronavirus nine days after attending the same event as Charles.