Queen Elizabeth II 2015
April 21, 2015 -- Elizabeth II, Queen of the United Kingdom and 15 other member states of the 53-nation Commonwealth of Nations, marks her 89th birthday. She acceded to the throne on February 6, 1952, and on September 10, 2015, she will have reigned for 63 years and 218 days, passing the record of Queen Victoria to become the longest-serving sovereign in the 1,000 year history of the British monarchy.
She was born in London on April 21, 1926, to the Duke and Duchess of York, and named Elizabeth Alexandra Mary. When Elizabeth was 10 her father acceded to the throne as George VI on the abdication of his elder brother Edward VIII, at which point the young princess became heir presumptive. In 1947 she married Lt Philip Mountbatten -- Prince Philip, Duke of Edinburgh -- with whom she has four children, Charles, Anne, Andrew and Edward.
Her reign has encompassed major constitutional changes, such as devolution within the United Kingdom and the decolonisation of Africa.