The Queen is to socially distance herself at Windsor Castle with a reduced household as she follows Government guidance on the coronavirus pandemic.
Buckingham Palace announced that the 93-year-old head of state will decamp from London to the Berkshire royal residence on Thursday – a week earlier than she usually does for Easter Court.
She is understood to be in good health and is likely to stay there beyond the Easter period.
The monarch will be based at her favourite home with a reduced number of staff and will be following appropriate advice, a source said.
Prime Minister Boris Johnson has called on all people in the UK, particularly the over-70s, to avoid all non-essential contact and travel as part of unprecedented peacetime measures aimed at controlling the spread of Covid-19.
Elizabeth II, the nation’s longest reigning monarch, is due to celebrate her 94th birthday next month, and the risk of more severe symptoms from the coronavirus is greater for the elderly and those with pre-existing health conditions.
Buckingham Palace said public royal events with large numbers of people in the coming months would be cancelled or postponed.
Investitures will be rearranged and the annual Maundy Service at St George’s Chapel has been cancelled, the palace said.
The Queen’s audiences this week at Buckingham Palace will go ahead as planned, including receiving the Prime Minister, the commanding officer of HMS Queen Elizabeth and the Bishop of Hereford.
But future audiences will be reviewed on an ongoing basis, the palace said.
Buckingham Palace is still functioning as an office, but numbers of staff have been reduced and are likely to diminish further once the Queen moves to Windsor.
The Queen is not the only royal affected by the Government’s new advice.
Heir to the throne the Prince of Wales is 71 and the Duchess of Cornwall is 72.
Other working royals include the Queen’s cousins the Duke of Gloucester, 75, the Duke of Kent, 84, and Princess Alexandra, 83.
The Duke of Edinburgh, 98, has already been spending most of his time in the sanctuary of Wood Farm, a cottage on the Sandringham estate.
The palace said further announcements would be made on Trooping the Colour, the 75th anniversary of VE Day and a state visit by the Emperor and Empress of Japan, in consultation with the Government.
Emperor Naruhito and Empress Masakois are due to stay with the Queen at Windsor Castle in May and be feted with a ceremonial welcome and a grand state banquet, but the high-profile occasion is expected to be postponed.
The Queen’s garden parties at Buckingham Palace have been called off and the Palace of Holyroodhouse garden party in Edinburgh, which takes place in July, is under review.
The palace said in a statement: “As a sensible precaution and for practical reasons in the current circumstances, a number of changes are being made to the Queen’s diary.
“Her Majesty will move to Windsor Castle for the Easter period on Thursday 19 March, one week earlier than planned. It is likely the Queen will stay there beyond the Easter period.
“In consultation with the Medical Household and Government, a number of public events with large numbers of people due to have been attended by the Queen, and other members of the royal family, in the coming months will be cancelled or postponed.”
An investiture had been due to take place at the palace on Wednesday.
Sixty-one recipients, accompanied by guests, were due to gather in the ballroom to collect a range of accolades, from MBEs to knighthoods and damehoods.
The recipients have been informed and the event will be rescheduled at a later date.
The Queen wore gloves for the first time at a palace investiture on March 3, while Charles has been welcoming guests with a namaste.
Investitures are planned months in advance, with guests travelling from all over the country to the Queen’s London home.
The Easter period is expected to be a quiet one for the monarch, as is usual, a source said.
Each year, the Queen takes up official residence in Windsor for a month over Easter between March and April, known as Easter Court.
The Queen also usually hosts a Dine and Sleep event during her stay when guests are given a bed for the night in the castle, but this will undoubtedly not take place.
Famous guests in the past have included director Tim Burton, actress Helena Bonham Carter, Bond star Daniel Craig and actress Rachel Weisz.