'Crown Headache' Dogged Diana at Wedding

Diana may have had her first inkling of the pain of being a British royal as she suffered an agonizing headache throughout her wedding day from the tiara attached to her head. "She had a cracking headache because she wasn't used to wearing a tiara all morning," her aristocrat brother Charles Spencer tells Entertainment Tonight. Despite the pain, "she seemed incredibly relaxed and happy," added Spencer, who was just 16 when his big sis became a princess.

"She was just my big sister. But when I walked in that day I thought, 'My goodness, they've transformed her into a very beautiful woman," he recalls. "She become that day a sort of fairytale princess. It was almost like she was handed over to the world." (More Princess Diana stories.)