Queen Elizabeth II is a force of stability in a turbulent, changing world. Revered for her calm dignity and sense of duty, the queen has rarely put a foot wrong in her 70 years on the British throne. Her extraordinary reign has seen many changes: in 1953, the year of her Coronation, Winston Churchill was prime minister, Harry Truman President of the United States, and Joseph Stalin leader of the Soviet Union. The Queen rarely lets her guard slip, but when she does, she often reveals a biting wit.