The 52-year-old appeared on the US version of the BBC’s hit show Who Do You Think You Are? which sees celebrities explore their family tree, often with extraordinary results.
However, Courtney hoped to find her distant relatives had achieved all sorts of heroic greatness, only to learn that they’d murdered royalty.
Speaking on The Late Show with Stephen Colbert, Courtney’s former Friends star and executive producer of the reality series, Lisa Kudrow revealed the mother-of-one was in for a shock.
“She was hoping that her family were good people, and no-one murdered anyone,” she said. “And it turns out her ancestors murdered the King of England.”
Courtney’s shock past comes after Danny Dyer discovered he was descended from royalty and related to Thomas Crowell.
Lisa’s confession comes after she recently recalled a horrifying sexist incident on the set of Friends after being confronted by unnamed guest star.
Appearing on US TV’s Watch What Happens Live, she told host Andy Cohen about the time was called “f**kable” after she put makeup on.
“I rehearsed without makeup most of the week,” she explained. “And then on show night I’m in hair and makeup and I was told, ‘Oh wow, NOW you’re’ – can I say it? ‘Now you’re f**kable.’”
She added that she later told her co-star and Top Gear host Matt LeBlanc, because “he’s like a big brother”.
Who Do You Think You Are? US premieres on TLC on March 5.