Queen Elizabeth II smiles as she meets people being helped by the Prince's Trust at the Prince's Trust Center in Kennington on March 8, 2016, in London, England. #

On June 2, 1931, Britain's Queen Mary, left, with 5-year-old Princess Elizabeth (later to become Queen Elizabeth II), accompanied by the lady Elizabeth Bowes Lyon, the Duchess of York, right, returning to Buckingham Palace, London, after the Trooping of the Colour Cermony. #

The little princess, age 11, appears on the balcony of Buckingham Palace on the occasion of the coronation of her father, King George VI, on May 12, 1937, in London. #

Princess Elizabeth celebrates her 13th birthday on April 21, 1939. The Princess was allowed to plan her own day, as it was her birthday, and after opening her presents in the morning, she went riding in Windsor Great Park with the King and Princess Margaret, her younger sister. #

Performing one of the many public duties she will be called on to perform as a member of the Royal House, Princess Elizabeth, heiress apparent to the British throne, broadcasts a three-minute speech to British girls and boys evacuated overseas on October 22, 1940, in London, England. She is joined in bidding good-night to her listeners by her sister, Princess Margaret Rose. #

Princess Elizabeth, center, ties knots under the watchful eyes of an expert at Buckingham Palace, on January 9, 1943, in London. The white stripes on her pocket proclaim her to be a Girl Guides patrol leader. #

Queen Elizabeth II and Prince Philip are a study in concentration in Schefferville, as they listen to explanation on workings of an iron-ore mine on another stop in their royal tour of Canada on June 20, 1959. #

Queen Elizabeth II addresses a vast gathering of more than a quarter of a million at the Ramlila Grounds, a huge public meeting place outside the walls of Old Delhi, India, on January 28, 1961. It was by far the largest audience ever directly addressed by the Sovereign. #

Queen Elizabeth II and Prince Philip fly back from a visit to Yorkshire in an Andover of the Queen's Flight, in a photo taken during the filming of the joint ITV-BBC film documentary, The Royal Family in 1969. #

Queen Elizabeth laughs, alongside her husband Prince Philip, as they drive through the crowd of athletes and officials during the Closing Ceremony of the 12th Commonwealth Games, in the Queen Elizabeth II Jubilee Sports Centre, in Brisbane, Australia, on October 9, 1982. #

The park superintendent Bob Binnewies points out highlights from Inspiration Point to Queen Elizabeth II during her visit to Yosemite National Park, in California, on March 5, 1983. #

Queen Elizabeth walks with her husband Prince Philip through the Royal Gallery after delivering her speech during the State Opening of Parliament at the Houses of Parliament in London on November 18, 2009. #

Britain's Queen Elizabeth II and Prince Philip, left, inspect the horses in the parade ring before the Derby race at Epsom Derby, Epsom, southern England, on June 2, 2012, the first official day of the Queen's Diamond Jubilee celebrations. #

A local youth takes a selfie photograph in front of Queen Elizabeth II during a visit to St George's indoor market on June 24, 2014, in Belfast, Northern Ireland. #

Prince George of Cambridge talks to Queen Elizabeth outside the Church of St. Mary Magdalene on the Sandringham Estate for the christening of Princess Charlotte of Cambridge on July 5, 2015, in King's Lynn, England. #

The German Chancellor Angela Merkel, left, and Britain's Queen Elizabeth II, right, smile as a little robot waves to the Queen during a reception at the Technische Universitaet, or Technical University, in Berlin, Germany, on June 24, 2015. #

Four generations pose together in this handout image released by Buckingham Palace on April 20, 2016. From left: Prince Charles, Prince of Wales; Queen Elizabeth II; Prince George; and Prince William, Duke of Cambridge, pose during a Royal Mail photoshoot for a stamp sheet to mark the 90th birthday of Queen Elizabeth II in the White Drawing Room at Buckingham Palace in the summer of 2015 in London, England. #