It's a day that will live in history: As Big Ben struck 11:18 on the morning of April 29, 2011, Prince William of Wales and Catherine Middleton of Bucklebury—you might know her as Kate—became the Duke and Duchess of Cambridge.
Oprah may not have been an invited guest, but she and the audience are having a royal celebration of their own. Donning hats of all shapes and sizes is a British tradition—the new duchess herself often makes fashion statements in stunning millinery—so Oprah and the entire audience took a cue from the other side of the pond. "I've said for years we have the best-dressed audience in television, " she says. "I know I am a hat person, but I didn't know this many people had hats. You all look fantastic. ... You all look like you could be at the real wedding, the real royal wedding."