Davina McCall stars in "Who do you think you are?" BBC

MY introduction to Who Do You Think You Are? was via Chris Moyles. After exploring his history for the series, the Radio 1 DJ told listeners in ­January: “Unlike a lot of the Who Do You Think You Are? shows, I didn’t go to Auschwitz. Pretty much everyone goes there, whether or not they’re Jewish.”

Instead of ­picking up on the shockingly far-reaching implications of the frequency of visits made by celebs to the Nazi death camp, he turned it into a ­punchline. Special.

Well, it will please Moyles to know that Davina McCall makes no detours to ­Poland to ­explore her ­ancestry. Since her mum was French, she merely crosses the Channel.

She does, however, discover that her great grandfather stood staunchly opposed to the wave of anti-Semitic ­feelings at the beginning of the last century.

Celestin ­Hennion was ­credited with modernising the French ­police force. He also played a major role in the outcry over ­the Dreyfus Affair, which saw an artillery officer wrongly ­imprisoned on the South American penal colony ­of Devil’s ­Island on an ­espionage charge because he was Jewish.

Impressive, but the English side of McCall’s family is not without stature. Her grandmother thinks she might be an illegitimate descendant of George IV – you know, the one played by Hugh Laurie in Blackadder the Third.

And her great-grandfather (times four) James Thomas Bedborough was an eminent stonemason partly responsible for the overhaul of Windsor Castle. He was, it seems, a man of great vision and even greater overspending. When he died, he left such debts that two of his sons killed themselves.

When historians repeatedly tell McCall that these are ancestors to be proud of, the presenter, who was estranged from her mother until her death last year, swells with a new pride for her family.

I’m surprised to say it’s all so fascinating that watching the Big Brother host leafing though old newspapers doesn’t quite do her ­stories justice. I want a three-part ­Sunday night costume ­drama, with Dame Judi Dench or McCall playing her lusty scullery wench ancestor being ravished by the blimpy Prince Regent, ­before she is evicted from the Big Brother house – I mean, ­Buckingham Palace.