Elizabeth Alexandra Mary Windsor was born on 21 April 1926 at her maternal grandfather's London house to her parents, the then-Duke and Duchess of York. She was educated privately at home, and when she turned 18 in 1944, she insisted upon joining the Auxiliary Territorial Service (ATS), the women's branch of the British Army, during the Second World War. Princess Elizabeth announced her engagement to Prince Philip of Greece and Denmark. as he was originally titled, on 9 July 1947 and they got married in London's Westminster Abbey on 20 November 1947, with him becoming Prince Philip, Duke of Edinburgh.