The palace marked the occasion with an adorable photo of the couple with a card made by great-grandchildren Prince George, Princess Charlotte and Prince Louis

Their lasting marriage is one of the most enviable in British royal history—today, Queen Elizabeth, 94, and Prince Philip, 99, celebrate their 73rd wedding anniversary after they wedded at Westminster Abbey on November 20, 1947.

The occasion was marked by an adorable photo of the couple reading a colourful card made by their great-grandchildren Prince George, Princess Charlotte and Prince Louis, amongst other greeting cards and well-wishing letters.

The photo was captured earlier this week by photographer Chris Jackson in the Oak Room at Windsor Castle, where the Queen and Philip are currently quarantining together, amidst the United Kingdom’s second national lockdown.

The Queen’s last public appearance was during a scaled-back Remembrance Day service on November 8, where she participated in a two-minute silence from the balcony of the Foreign, Commonwealth and Development Office building. Prince Charles laid a wreath on her behalf.

As for Philip, the senior royal officially retired from his royal duties on August 2, 2017, retreating to the Wood Farm on Sandringham Estate and only making an appearance for family events like weddings and baptisms.

The ongoing pandemic has given the royal couple the opportunity to spend more time together. The Queen has been quarantining with Philip since March at Windsor Castle in Berkshire, and they also took a summer vacation to Balmoral Castle in Scotland and Sandringham Estate in Norfolk with a small team of staff.

With the second lockdown in effect in the UK, however, it is unclear if the couple will be able to make the annual trip to Sandringham Estate, where the British royal family gathers every year to celebrate the holidays together.