On his episode of Who Do You Think You Are? David Suchet, the actor most famous for his portrayal of TV sleuth Hercule Poirot, turns his ‘little grey cells’ to a mystery closer to home – his own heritage. Many questions remain unanswered – is there ‘water in the blood’ which might explain David’s enduring love of boats? When and why was the family surname changed from Suchedowitz to Suchet? And where in Europe do his roots lie?

First David explores the English ancestors of his maternal grandmother, Elsie Jezzard, a music hall artist from whom he suspects he inherited his love of acting. David discovers that Elsie’s grandfather George was a master mariner and, intrigued by this ‘water connection’, heads to the National Maritime Museum to find out more. Documents there plot a distinguished career spanning nearly four decades, but also reveal that a ship under George’s charge sank off the coast of Suffolk on 28 May 1860.

At Lowestoft Library, David finds an old newspaper report on the devastating storm that destroyed George’s ship, the Hannah, along with more than 150 other vessels. George Jezzard escaped death thanks to the heroic efforts of a man named John Cragie, who rescued the crew of the stricken vessel moments before it sank beneath the waves. David even manages to track down the descendant of the man who saved his 3x great grandfather’s life.

Next David turns his attention to his much-loved maternal grandfather, press photographer Jimmy Jarché. But Jimmy’s lineage is shrouded in mystery. His father, Arnold ‘Jarchy’, also a photographer, was a Jewish émigré who arrived in the UK from Paris in the late 1800s. But were Arnold and his wife French, as the family always believed? “The plot thickens,” says David. “There’s obviously family confusion here – or people not wanting to know what went on.”

After visiting the site of Arnold’s first London studio, David heads to Paris in search of the ‘Eiffel Tower Studio’ his ancestor claimed to have run in the fashionable French capital. But at Paris’s Musée Carnavalet he discovers that no such studio ever existed. “I think when [Arnold] gets to London, he wants to impress,” says David. “And knowing us Brits, we could be quite impressed by that sense of foreignness, of mystique. Good for him!”

But if the Eiffel Tower Studio was a fabrication, what else had Arnold lied about – his nationality, perhaps? David finds the answer at the French National Archives, where his great grandparents’ marriage certificate proves that the couple weren’t French, but Russian. They had fled anti-Semitism in their home country to start anew in Paris. “Very brave, very courageous,” says David. “That refugee background gives one a certain need to achieve – you’re going to keep going, you’re not going to give up.”

Like the Jarchys, David’s father’s family the Suchets were of Jewish East European descent. Their name was once Suchedowitz, and David is determined to discover its origins. Though his South African cousin Mavis and newscaster brother John both provide valuable clues, for the final pieces of the puzzle David must travel to Eastern Europe.

In Lithuania David enlists the help of a local genealogist, who helps him decipher the records and find the original Jewish form of his unusual name: Shokhet. He also learns of his great grandfather Jacob’s ingenious ruse to help the family escape anti-Semitic persecution in the Russian ‘Pale of Settlement’, for safety and freedom in Prussia. David’s final destination is Tryskiai, his family’s home town. “It’s the end of my journey,” he says. “But it was the beginning of my family’s.”