For example, https://theconversation.com/the-french-revolution-executed-royals-and-nobles-yes-but-most-people-killed-were-commoners-200455 which cites this book https://www.amazon.com/Incidence-Terror-During-French-Revolution/dp/0844612111 (unavailable online as far as I can tell.)
I'd also highly recommend Mike Duncan's Revolutions podcast series on the French Revolution.
He's demanding that everyone conform to his narrow worldview... in the name of preserving our differences?
That's some impressive mental gymnastics, even for a Pope.