Best of 2011

Remembering Princess Diana on Her 55th Birthday: Images We Can't Forget

She was the most photographed woman in the world. Here, the shots that stand the test of time

Sleeping Beauty

"I felt compelled to perform," Diana had said, "To do my engagements and not let people down." Still, she filled her schedule – but couldn't help but fall asleep during a 1981 event. (It was later revealed that, at the time, she was pregnant with William.