Dating her sister
The love affair between Charles and Diana does not begin with them. It starts with Charles and Lady Sarah Spencer, Diana's older sister. They dated briefly until Lady Sarah became too open with the press. Aside from revealing her personal troubles, she informed reporters she would never marry Charles, whether he was the garbage collector or the King of England. Charles, understandably enraged, ended the relationship soon after. While they were still together, he went to Althorp House, the Spencers' home since 1508. He met Diana, 16, for the first time there.
It all started with the light switches
Everything started out innocently, not only because Charles was seeing Diana's sister, but also because he was 29 at the time and Diana was still an adolescent. The future king arrived at the 1,500-acre Althorp House for a weekend of hunting and afterwards remarked on “how much fun” Diana was. Diana, for one, was captivated, telling her piano teacher, “I've finally met him!” She even showed Charles around Althorp's art gallery because she knew where the covered light switches were, and Sarah didn't, which infuriated her older sister. Charles would remember it for the rest of his life.