Soldiers march down the Mall during the Trooping the Colour ceremony to mark Queen Elizabeth II's 93rd birthday in London, Britain,on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace. (Photos: Xinhua)

Britain's Queen Elizabeth II comes back to Buckingham Palace during the Trooping the Colour ceremony to mark her 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Prince Harry, Duke of Sussex, and his wife Meghan Markle, Duchess of Sussex, depart from Buckingham Palace during the Trooping the Colour ceremony to mark Queen Elizabeth II's 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Prince Harry, Duke of Sussex, and his wife Meghan Markle, Duchess of Sussex, depart from Buckingham Palace during the Trooping the Colour ceremony to mark Queen Elizabeth II's 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Queen Elizabeth II (C) and her family members are seen on the balcony of Buckingham Palace during the Trooping the Colour ceremony to mark her 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Queen Elizabeth II (C) and her family members are seen on the balcony of Buckingham Palace during the Trooping the Colour ceremony to mark her 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Queen Elizabeth II departs from Buckingham Palace during the Trooping the Colour ceremony to mark her 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

People gather in front of Buckingham Palace during the Trooping the Colour ceremony to mark Queen Elizabeth II's 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Queen Elizabeth II departs from Buckingham Palace during the Trooping the Colour ceremony to mark her 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Camilla (L), Duchess of Cornwall, and Catherine, Duchess of Cambridge, arrive at Buckingham Palace during the Trooping the Colour ceremony to mark Queen Elizabeth II's 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Camilla (L), Duchess of Cornwall, and Catherine, Duchess of Cambridge, depart from Buckingham Palace during the Trooping the Colour ceremony to mark Queen Elizabeth II's 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.

Britain's Queen Elizabeth II comes back to Buckingham Palace during the Trooping the Colour ceremony to mark her 93rd birthday in London, Britain, on June 8, 2019. Queen Elizabeth celebrated her official 93rd birthday in London Saturday, with a family gathering on the balcony at Buckingham Palace.