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

The couple have enjoyed the longest marriage in British royal history

Lieutenant Philip Mountbatten, prior to his marriage to Princess Elizabeth, saluting as he resumes his attendance at the Royal Naval Officers School in 1947. Getty Images

Philip Mountbatten, prior to his marriage to Princess Elizabeth, batting at the nets during cricket practice while in the Royal Navy in 1947. Getty Images

Princess Elizabeth and Prince Philip, Duke of Edinburgh at Buckingham Palace shortly before their wedding in 1947. Getty Images

Queen Elizabeth II and her husband, the Duke of Edinburgh, on their wedding day in 1947. Getty Images

Crowds gathering outside Buckingham Palace on the wedding day. Getty Images

Members of the British royal family on the balcony at Buckingham Palace after the wedding of Princess Elizabeth and Philip Mountbatten. Getty Images

The marriage register of Princess Elizabeth and Lieutenant Philip Mountbatten, bearing the signatures of Philip and Elizabeth, the King and Queen and members of the Royal Family. Getty Images

Princess Elizabeth, King George VI, Princess Margaret Rose, Queen Elizabeth and Prince Philip walking through streets on their way to wedding of Patricia Mountbatten to Baron Brabour. Getty Images

Queen Elizabeth talking to Prince Philip (second right), the Duke of Edinburgh, at the Royal Horse Show at Windsor, England. Getty Images

Portrait of Queen Elizabeth II and Prince Philip, the Duke of Edinburgh, circa 1952. Getty Images

Princess Elizabeth and Prince Philip with their baby daughter Princess Anne following her christening, at Buckingham Palace in 1950. Getty Images

US President Eisenhower (centre) with the British Royal family: Prince Philip, Princess Anne, Queen Elizabeth, Prince Charles and Captain John Eisenhower, at Balmoral Castle in 1959. Getty Images

Queen Elizabeth II, Prince Philip and their three children, Prince Charles, Princess Anne, and Prince Andrew in Balmoral on September 8, 1960.

Queen Elizabeth and Prince Philip leave Manchester by train in 1961. Getty Images

Queen Elizabeth and Prince Philip presenting the Jules Rimet trophy to the England captain, Bobby Moore, after the teams World Cup final victory over West Germany in 1966. Getty Images

Prince Charles wearing a crown and robes after a ceremony where he was invested as the Prince of Wales, with Queen Elizabeth and Prince Philip at Caernarvon Castle, Wales, in 1969. Getty Images

Queen Elizabeth and Prince Philip during the Royal Progress trip via boat down the River Thames to mark the Silver Jubilee in 1977. Getty Images

Queen Elizabeth ll and Prince Philip, Duke of Edinburgh entertain Sheikh Zayed on board the Royal Yacht Britannia during their State Visit in 1979. Anwar Hussein/Getty Images

Pope John Paul II with Queen Elizabeth and Prince Philip during a Royal Tour of Italy in 1980. Getty Images

The wedding of Prince Charles and Lady Diana Spencer at St Paul's Cathedral in 1981. Behind them are Queen Elizabeth and Prince Philip. Getty Images

Prince Charles and Lady Diana Spencer with Queen Elizabeth and Prince Philip on the balcony at Buckingham Palace after their marriage ceremony in 1981. Getty Images

Princess Diana holds her son Prince William in her arms in Buckingham Palace with Prince Charles, Prince Philip, Queen Elizabeth, the Queen Mother. The Prince was christened in 1982. Getty Images

Queen Elizabeth and Prince Philip appear with The Queen Mother during celebrations to mark her 101st in 2001. Getty Images

Queen Elizabeth and Prince Philip ride in the Golden State Carriage at the head of a parade from Buckingham Palace to St Paul's Cathedral celebrating the Queen's Golden Jubilee in 2002. Getty Images

Queen Elizabeth smiles at the crowd from the balcony of Buckingham Palace as Prince Harry, Prince William, Princess Anne and Prince Philip look on after attending the Trooping of the Colour in 2003. Getty Images

Queen Elizabeth II and Prince Philip, Duke of Edinburgh arrive at Ascot Racecourse on June 18, 2008, in Ascot, England. Getty Images

The Sultan of Oman, Sultan Qaboos bin Said, presents Britain’s Queen Elizabeth II with a gold musical Faberge style egg as Prince Philip watches on at the royal palace in Oman.

Queen Elizabeth II holding the hand of her husband Prince Philip, Duke of Edinburgh as she arrives to address to the House of Lords, during the State Opening of Parliament in Westminster. EPA

Britain's Queen Elizabeth II (L) and her husband Prince Philip (R) stand next to the President of the United Arab Emirates Sheikh Khalifa bin Zayed al-Nahayan during a Ceremonial Welcome in the town of Windsor, west of London, on April 30, 2013. AFP

Britain's Queen Elizabeth II speaks to Prince Philip on the Queen's Stand during the Epsom Derby Day on Saturday, 2014. EPA

Queen Elizabeth II and Prince Philip, Duke of Edinburgh look at their homemade wedding anniversary card, given to them by their great grandchildren Prince George, Princess Charlotte and Prince Louis, in the Oak Room at Windsor Castle ahead of their 73rd wedding anniversary. Getty Images

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