Everything You Need to Know About Prince Charles' Relationship With Princess Diana's Elder Sister

Prince Charles originally dated Princess Diana's elder sister, Sarah Spencer, before he married the younger sibling. When Sarah started dating the king in 1977, she was 22, and he was 28, according to Marie Claire. Author Sarah Bradford detailed how the pair first connected at a private party at Windsor Castle during the Royal Ascot in her book, Diana: Finally, the Complete Story. 

As per Oprah Daily, Bradford mentioned in her book, "Prince Charles enjoyed Sarah's sparkiness and irreverent wit, and they made each other laugh." The pair continued to spend more time together after that. In Diana: A Princess and Her Troubled Marriage, it was revealed that Sarah and Prince Charles attended theater productions, polo matches, and 'country house parties.' The Queen even extended an invitation to Sarah to come to Balmoral. They seemed to have a vacation together to the Swiss ski resort of Klosters.

The relationship seemed pretty serious at first, but it ended after only a single year of dating. Regretfully, Lady Sarah also discussed their connection with the media, which reportedly upset Charles. According to royal writer Tina Brown, when Sarah eventually admitted that an article including her words was going to be published, he reportedly told her icily, "You've just done something extremely stupid."

Things ended abruptly just as Sarah and Prince Charles's relationship seemed to be becoming more serious. He ended their relationship when Sarah gave a startling interview to the media. In a piece published in Mirror, the journalist's notorious 1978 interview with Sarah was discussed. According to his memory, Sarah "was disarmingly frank about her boyfriend."

Sarah said at the time, "Charles makes me laugh a lot. I really enjoy being with him." However, as reported by Time, she said firmly, "There is no chance of my marrying him. I'm not in love with him. And I wouldn't marry anyone I didn't love whether he were the dustman or the King of England."

When it comes to Diana, Charles' first encounter with her occurred in November 1977 while on a hunting trip at the Spencer family's opulent rural house, Althorp, thanks to his friendship with Sarah. After initially approving of their relationship, Sarah referred to herself as 'Cupid' for having introduced them. Sarah finally married Neil Edmuch McCorquodale in 1980 after deciding she did want to settle down with him.

PopSugar reported that while Sarah adopted his last name, she kept her title—he didn't have one—becoming Lady Sarah McCorquodale. As such, Lady McCorquodale helped her younger sister by serving as one of her ladies-in-waiting when Diana Spencer married Prince Charles and became Princess Diana in 1981; ostensibly, her official title was "Extra Lady-in-waiting." According to Town & Country, this job often included traveling with Princess Diana on royal visits and assisting her with her official responsibilities. For example, Sarah traveled to Nepal with Princess Diana in 1993.