Prince Charles and Duchess Camilla are returning to Clarence House.

The couple had been living in lockdown at their Birkhall estate in the Scottish highlands. The Prince of Wales, 71, had tested positive for COVID-19 shortly after he arrived in the country in mid-March, and he and Camilla remained there during the lockdown period.

Now, nearly three months later, the royals will return to their London residence ahead of a June 18 ceremony at Clarence House.

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Emmanuel Macron will join Charles & Camilla at Clarence House

Upon their return to Clarence House, Charles and Camilla are scheduled to host French President Emmanuel Macron on Thursday, June 18. The day marks the 80th anniversary of Charles de Gaulle's "Appel du 18 Juin" — his June 18, 1940, speech made from London on French resistance against the country's Nazi occupiers during the Second World War.

The French president will attend a ceremony at Clarence House on Thursday to mark the occasion, with Charles and Camilla representing the royal family on behalf of the U.K. government. As People reports, the event will follow social distancing guidelines.

Today, the Twitter account of Clarence House also acknowledged another 80th anniversary, as Prince Charles took the salute in honour of the 1940 Battle of St Valery-en-Caux.

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Prince Charles & Duchess Camilla were quarantined in Birkhall 

Clarence House's Twitter video also gave a rare look at the entrance to Birkhall, which is located on the royal Balmoral Estate. Charles inherited the home after the death of Queen Elizabeth, the Queen Mother in 2002.

Birkhall is typically a summer residence for the Prince of Wales and Duchess of Cornwall. But Charles's COVID-19 diagnosis in March resulted in a brief self-isolation period for him and Camilla, which extended into a nearly three-month spring stay at the Scottish residence.