Happy Birthday, Princess Diana: 50 Rare Images of an Icon

Wedding of the Century
In 1981, Lady Diana Spencer marries Prince Charles at London's St. Paul's Cathedral in an elaborate gown with a 25-ft. (7.6 m) train. On April 29, 2011, her son William married Kate Middleton at Westminster Abbey, where the bride wore a much less intricate dress, designed by Sarah Burton for Alexander McQueen.

• Why Princess Diana Mattered