Josh Widdecombe's royal Who Do You Think You Are is the best reveal since Danny Dyer's

Over the 17 years Who Do You Think You Are? has been on air, producers have convinced some major stars to follow their family tree: Kate Winslet, Olivia Colman, Sir Ian McKellen and Derek Jacobi have all taken part, and this latest series, which started last night, will feature Dame Judi Dench.

Comedian Josh Widdicombe does not quite measure up to these British giants of acting, so the fact that he opened the 18th series of the BBC juggernaut could only mean one thing: he has a good bloodline to follow. It was quite a revelation.

His trip into history started with his own life story, which moved from his birthplace of east London to his “Enid Blyton-esque” Devon primary school, which was so remote there were only three other children in his year group.

“My greatest fear is that I come from a really boring family,” he worried – a legitimate concern when your genealogy is about to become an hour of primetime entertainment.

His father’s bloodline quickly looked to be the more interesting to trace, not least a long-standing family rumour that the Widdicombes are related to the creators of the Barings Bank, one of the oldest merchant banks in the UK, which collapsed in 1995.

There was a flash of excitement when a historian confirmed that Widdicombe was indeed related to one of the four Barings brothers, but it turned out that his ancestor was Charles – a man so bad at business he was cut out of the family fortune.

Not all was lost, though, as the same historian directed Widdicombe further back into his family history, to a promising man called Henry Rich, 1st Earl of Holland (Park in London).

From then on, the episode snowballed through a series of royal revelations, each more impressive than the next. Rich was revealed to be righthand man to Charles I, so close in fact that it was his job to accompany the king to the toilet.

As a royalist during the English Civil War, things didn’t end well for Rich, and Widdicombe found himself moved by the courage and stoicism of his ancestor as he read the speech he gave before he was beheaded.

In the speech, Rich said he was of “good stock”, which as we soon found out, was quite the understatement. His 13th great grandmother was Katherine Knollys, the first cousin of Queen Elizabeth I who is buried Westminster Abbey.

Widdicombe was amazed, but still his genealogical journey wasn’t over. Katherine’s daughter, Lettice (Henry Rich’s grandmother), was revealed to have been caught in a love triangle with Elizabeth I but escaped being sent to the Tower of London because of her familial connections.

“Every time I think we’ve topped out now,” said Widdicombe.

“This is going to tail off in a minute. Surely this documentary has peaked.”

Not quite, as a trip to Westminster confirmed that Katherine was indeed the daughter of Mary Boleyn, sister of Anne – Widdicombe’s 14 times great grand-aunt. In fact, some “respected historians” believe that Katherine was actually the result of an affair between Mary and her sister’s husband, one King Henry VIII.

And yet we still weren’t at the end. Widdicombe’s ancestry was eventually traced all the way back to 1239 and confirmed Josh Widdicombe is descended from King Edward I.

Moreover, not only does he have English blue blood, he also has French royalty in his veins – Edward’s wife was Marguerite of France, daughter of Philip III of France.

“Be honest, as a historian are you massively jealous?” Widdicombe asked his guide, to which he replied, “Massively.”

Who Do You Think You Are always runs the risk of becoming a boring history lesson about people we’ve never heard of and don’t care about.

And while it took almost 45 minutes for the royal connections to arrive, they were certainly worth the wait. Episodes like this prove genealogy – even someone else’s – is still fertile ground for TV.

The comedian’s reaction was rather muted – especially compared to Danny Dyer’s who famously found he was related to King Edward III on the programme – but he was clearly delighted with his “star-studded” family tree. And who wouldn’t be thrilled to find they were connected to some of British history’s all-stars? Beat that, Dame Judi.