LONDON, UNITED KINGDOM  - MARCH 18:  Queen Elizabeth II, accompanied by Prince William, Duke of Cambridge, receives the Ambassador of Austria His Excellency Dr Martin Eichtinger and his wife Mrs Elchtinger as he presents his credentials during a private audience at Buckingham Palace on March 18, 2015 in London, England. It is the first time William has accompanied his grandmother at the regular royal duty and serves as part of his training as the future king. (Photo by Steve Parsons - WPA Pool/Getty Images)