Who Do You Think You Are? on BBC One: The most memorable episodes

Isobel Frodsham

Over the years, BBC One’s Who Do You Think You Are has entertained and shocked viewers with its incredible discoveries from a variety of actors, celebrities, musicians and politicians.

Tonight’s episode features Oscar award-winning actress Kate Winslet, 43, who delves into her heritage to discover a Swedish connection with a tragic ending and a relative who was a drummer boy in the Grenadier Guards.

She finds out her maternal great-great-great-great grandfather Anders Jonsson had to steal to feed his family, before losing his baby son and dying in prison months later.

Meanwhile on her paternal side, Winslet discovers her great-great-great grandfather, William Colquhoun, worked his way up to be a drum major in the British army.

But her emotional discoveries about her relatives are far from unusual in the heart-wrenching programme.

Here are five of the top discoveries of Who Do You Think You Are?.

1) Danny Dyer

Danny Dyer has made a living off playing the classic East End hard man who is just a normal guy. But Dyer was delighted – as were audiences – to discover his lineage traces back to Earl of Essex Thomas Cromwell and to King Edward II of England.

Danny's fascinating episode led to his own show, Danny Dyer's Right Royal Family (BBC/Stephen Perry)

Dyer, who is the father of Love Island winner Dani, 23, subsequently had a spinoff show called Danny Dyer's Right Royal Family, where he researched the lives of his ancestors.

2) Sir Matthew Pinsent

Olympic gold medallist Sir Matthew Pinsent began the programme with a tragic tale. He discovered his great uncle, George McPherson, committed suicide during one of the first great tank battles of the war, the Somme. He later discovers his great grandfather, David Landale, worked for Jardine-Matheson in Shanghai, a firm that was heavily involved in the opium trade.

Sir Matthew's lineage dates back to Adam and Eve (PA)

Meanwhile, some further digging into his maternal side of the family reveals he is related to Lord William Howard, the uncle of Henry VIII’s fifth wife Catherine, Edward I and William the Conqueror. A medieval roll later discovered claimed the Norman king was descended from Adam and Eve - and ultimately to God.

3) Natasha Kaplinsky

After recounting her father’s background – that he had grown up in South Africa and was forced to leave with 24 hours notice - newsreader Natasha Kaplinsky discovers her father lead a student demonstration in support of a black lecturer, forcing him to flee.

Natasha Kaplinsky was delighted to discover her relative was an apothecary to royalty (Stuart Wilson/Getty Images)

She also discovers her many-times great grandfather, Benjamin Charlewood, was a master of the Society in 1760, and an apothecary to the households of George II and III.

Kaplinsky also visited Belarus to research her Jewish heritage, where she discovers a brother of her grandfather, Izak, joined the partisans, and worked to protect Jews in hiding from the clutches of the Nazis.

4) Ainsley Harriott

Celebrity chef Ainsley Harriott visited the West Indies to uncover his roots. He believed he knew a lot about his ancestors – such as his great-grandfather was in the colonial West India Regiment.

Ainsley Harriott discovered far more than he was expecting on the show (Eamonn M. McCormack/Getty Images)

He also found an interesting fact about one of his ancestors, an unmarried "free black woman, who purchased seven houses after gathering enough money. To his surprise, he also found his great-great-great grandfather, James Gordon Harriott, wasn't a black slave, but a white slave owner.

5) Sir Ian McKellen

The veteran actor Sir Ian McKellen was somewhat melancholic when he began digging into his history. However, he was left delighted after discovering great uncle, Frank Lowes, was also an actor.

Sir Ian found out acting runs in his genes (Dave Benett)

His great-great-grandfather, Robert Lowes, campaigned for a half-holiday for Manchester's workers on Saturdays, an event that led to the evolution of the weekend.

Who Do You Think You Are? airs tonight at 9pm on BBC1

---Watch the latest videos from Yahoo UK---