In the photo taken by Chris Jackson (Getty Images), the Queen and the Duke of Edinburgh appear on a greeting card made by Prince George, Princess Charlotte and Prince Louis, children of the Duke of Cambridge, along with other greeting cards and letters received on the occasion.

The photo was taken at Windsor Castle this week.

Foto Chris Jackson / Getty Images

Queen Elizabeth II of Great Britain and Northern Ireland and Prince Philip, Duke of Edinburgh, are celebrating their 73rd wedding anniversary on Friday.

The two met at the wedding of Princess Marina of Greece and Denmark to Prince George, Duke of Kent, in 1934.

After a third meeting in July 1939, the future queen, who was 13 years old, fell in love with Philip and they began to correspond, according to

Elizabeth and Philip were secretly engaged in 1946, and King George VI ordered that any formal engagement be postponed until his daughter was 21 in April 1947.

Their engagement was officially announced on July 9, 1947.

The wedding ceremony of Princess Elizabeth of Great Britain with Prince Philip took place on November 20, 1947, in Westminster Abbey, London. The queen had eight bridesmaids, including her sister Princess Margaret. Two thousand people were invited to the wedding, and among those present at the ceremony were King Mihai I and his mother, Queen Elena.

Elizabeth was the tenth member of the British royal family to marry at Westminster Abbey.

Prince Philip was appointed Duke of Edinburgh, Earl of Merioneth and Baron Greenwich of Greenwich on the morning of the wedding.

The ceremony was recorded and broadcast by BBC Radio to around 200 million people worldwide.