The late Princess Diana's brother even shared a "terrible" discovery he'd made regarding one of their royal relatives, King Charles I. In 2015, the Earl spoke to NPR about Charles I, of whom the father-of-seven is a direct descendant.
Having researched a book about the monarch, Killers of the King: The Men Who Dared to Execute Charles I, Charles revealed that he had learned a lot about his ancestor, some of which was regrettable.
He said: "I started researching the book thinking I'd just feel very sorry for Charles I, you know, because he was put on trial in a court that shouldn't have existed and he had tried his best. And, yes, he wasn't the best ruler, but he did try.
"But as I researched it, I realised that he really was responsible for so much of this bloodshed... Five percent of English people were killed in the war, and it was a terrible time."
This grim discovery led the author to add an acknowledgement to: "the extremely brave men who put a defeated and distrusted king on trial, and saw through what they sincerely believed had to be done".
Charles I's reign was marked by authoritarian rule and his efforts to limit the rights and freedoms of his subjects, leading to his conflict with Parliament and the outbreak of the English Civil War.
The war lasted from 1642 to 1651 and resulted in the deaths of an estimated 200,000 people.
Drawing a link to the present day, the Earl concluded: "The royal family we have today is alive and kicking very much because of what happened back in the mid-17th century, where the British thought, 'Right, we do want to continue having a ruler. But we're not going to be dealt with in a way that is basically dictatorial'."
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