Who Do You Think You Are?

First up is Harry Potter star Daniel Radcliffe, who discovers that the robbery of his great-grandfather's Hatton Garden jewellery business was far more dark and dramatic than he ever imagined, while a cache of his great-great-uncle's letters reveal a heart-wrenching First World War love story.

Actress Naomie Harris's dramatic discoveries in this edition of the show in which celebrities research their family trees inspires her to anger, sadness and tears of joy. On a journey from Trinidad to Grenada to Jamaica, she learns of her great-great-great-great- grandfather's involvement in the exploitation of so-called liberated Africans shortly after the abolition of slavery, is delighted to discover the identify of her African five-times-great grandmother, and uncovers a family story of tragic poverty in Jamaica's capital of Kingston.

In a first for the series, father-and-son comedy double-act Jack and Michael Whitehall join forces to investigate their family tree. They discover the tragedy that left Jack's great grandfather (Michael's grandfather) an orphan. And tracing their line back to Wales in the 1830s, they find out about a Tory ancestor's role in opposing the Chartist movement for wider voting rights.

Oscar-winning actress Kate Winslet follows a rumour of Scandinavian ancestry on her late mother Sally's side of the family and is delighted when it turns out to be true and that she has Swedish heritage. However, her joy turns to tears and anger when she uncovers the extreme hardships her ancestors endured, from famine to flogging and imprisonment. Switching to her father's side of the family, Kate finds a drummer boy in the Grenadier Guards and, this time, an unusually positive encounter with prison.

Canadian comedian Katherine Ryan's investigation of her family history leads her to a Methodist minister and his family in colonial Nova Scotia, cod traders in Newfoundland, and eventually to her English roots in Dorset.

Comedian Paul Merton was very close to his late mum, and he knows that her Irish parents died when she was very young. Her father was a shadowy figure said to have been lost at sea. Paul pieces together his grandfather's story and discovers that he was involved in some of the key events leading to Irish independence in the 1920s, and that the true circumstances of his death were different from the story that has been handed down. In London, on his father's side, Paul traces a great-great-grandmother who was sent to prison for her part in an assault... involving a banjo.

Sharon Osbourne is open about her less-than-idyllic childhood and her remote relationship with her mother, but as she delves into her maternal family history and uncovers the difficult circumstances of her mother's and grandmother's lives, she is moved by what she discovers, from family break-up to a brush with the law. Further back, Sharon is astonished to discover that her great-grandmother was born in the United States, but as Sharon digs deeper in to the story she realises it's a case of the American Dream gone wrong. Sharon's great-great-grandparents, lured by the promise of work in a cotton mill town advertised as paradise, found the harsh reality very different.

Intrigued by family stories from his granddad Eddie, former TOWIE star and presenter Mark Wright investigates his dad's side of the family. Discovering Sephardi Jewish ancestry and a master swordsman living in late 17th-century Andalucía, Mark's journey takes him to Spain where he's astonished to finds out how his nine-times great-grandfather survived the terror of the Spanish Inquisition, while a less fortunate relative was burned at the stake.