Queen Elizabeth II and Prince Philip celebrate 73rd wedding anniversary - in pictures

The couple have enjoyed the longest marriage in British royal history

Britain's Queen Elizabeth II and Prince Philip marked their 73rd wedding anniversary on Friday by sharing a photograph of themselves opening a card from three of their great-grandchildren.

The photo, shared on social media, shows Britain's longest-reigning monarch and her husband seated on a sofa at Windsor Castle, reading the card made by Prince George, Princess Charlotte and Prince Louis, the children of their grandson, Prince William, and his wife, the Duchess of Cambridge. The card features a pop-up number 73.

Elizabeth was just 21 when she married Royal Navy Lt. Philip Mountbatten at Westminster Abbey on November 20, 1947. She has been queen since 1952, ruling longer than any other British monarch.

Her marriage to Prince Philip is also the longest for any British sovereign. The pair have four children - Prince Charles, Princess Anne, Prince Andrew and Prince Edward.

While Queen Elizabeth continues to carry out her duties, Prince Philip, 99, has retired from public life. With England under a national lockdown to control the Covid-19 pandemic, the couple are self-isolating at Windsor Castle.

Scroll through the gallery above to look back at the Queen and Prince Philip through the years