Bathed in beautiful sunshine, the grounds of Buckingham Palace are transformed by a sea of elegant hats and summer outfits.This was the scene as the Queen, accompanied by Prince Philip and wearing a summery peach coloured coat and hat, hosted the first Palace garden party of the year.Having made their entrance as the band played the National Anthem, the royal couple were greeted with applause by some 8,000 guests.One lucky invitee was American journalist Katie Couric, who has interviewed Princes William and Harry about their grandmother in the lead up to the Diamond Jubilee.Clearly impressed following her first introduction to the monarch, she told ABC News: "I had no idea what to expect. She looked beautiful. "She also revealed that the "quiet, lovely and charming" 86-year-old had spent more than two hours mingling, despite the heat.Helping her welcome the crowds were her children the Duke of York and Princess Anne, as well as cousins Prince and Princess Michael of Kent.Tuesday's event will be followed by a second Palace garden party on May 29.