The Queen is leaving London for Windsor Castle on Thursday, as she socially distances herself amid the coronavirus pandemic.
She is heading for the sanctuary of her Berkshire home a week earlier than she normally would at this time of year, and is expected to remain there beyond the Easter period.
The Queen, 93, carried out official duties the day before her planned departure, but held her weekly audience with Prime Minister Boris Johnson on the phone.
The monarch had planned to meet Mr Johnson face to face as usual.
Her Wednesday audience with the PM will, for the foreseeable future, take place on the phone.
The monarch did, however, hold two face-to-face audiences at the Palace.
She greeted Captain Angus Essenhigh, who is the new commanding officer of the Royal Navy warship HMS Queen Elizabeth, and his predecessor Commodore Stephen Moorhouse, in her private audience room.
There were no handshakes, only bows, as they chatted on separate seats around the fireplace.
The Queen also had an audience with Louise Tait, who was relinquishing her appointment as the Scottish communications secretary, the Court Circular – the daily record of official royal engagements – showed.
On Thursday, the Queen was meant to be carrying out an away-day of engagements in Cheshire, but the visit to Crewe and Macclesfield was postponed last week.
The Queen, who is understood to be in good health, will be based at Windsor with a reduced number of staff.
The castle is her favourite home when she is not away during the summer and at Christmas.
She will be following appropriate advice from her medical household and the Government.
Mr Johnson has called on everyone 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.
The Queen, the nation's longest reigning monarch, will 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 has said public royal events with large numbers of people in the coming months would be cancelled or postponed.
The annual Maundy Service, where the Queen hands out Maundy money on the Thursday before Easter, was due to take place at St George's Chapel in Windsor, but has been cancelled.
The Buckingham Palace garden parties have also been called off, and investitures will be rescheduled.
Princess Beatrice has cancelled her royal wedding reception in the palace gardens in May, but is still planning to wed in a small private ceremony if possible.
The Queen is not the only member of the royal family affected by the Government's advice on social distancing.
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 been spending most of his time at Wood Farm, a cottage on the Sandringham estate.
The Princess Royal, who turns 70 in August, the Duke and Duchess of Gloucester and the Earl of Wessex had engagements planned on Wednesday, including a visit by Anne to Guy's Campus at King's College London.
But they appear to have been cancelled or postponed as there was no sign of them in the Court Circular.