President Obama and first lady Michelle Obama welcome Britain's Queen Elizabeth II and the Duke of Edinburgh at Winfield House, the residence of the Ambassador of the U.S., in Regent's Park, London. (Associated Press)

Photo by: YUI MOK

President Obama and first lady Michelle Obama welcome Britain's Queen Elizabeth II and the Duke of Edinburgh at Winfield House, the residence of the Ambassador of the U.S., in Regent's Park, London. (Associated Press)