Lady Diana Spencer became the Princess she was known to be when she married the then Prince Charles on July 29, 1981. The royal was known for her philanthropy and charity work, which she continued long after separating from the monarch-to-be. But her style was also a hit with fans, and in particular her wedding dress – but Princess Diana had no idea there was a ‘secret’ backup on standby for the big day. The nuptials were a turning point for the royals. Fans adored Princess Diana, and she would spend the next several years showing what work The Firm does to help those in need. The 20-year-old …