In a first for the series, father-and-son comedy double-act Jack and Michael Whitehall join forces to investigate their family tree.

Oscar-winning actor Kate Winslet follows a rumour of Scandinavian ancestry on her mother's side of the family and is delighted to find that she has Swedish heritage.

Oscar-winning actor Kate Winslet follows a rumour of Scandinavian ancestry on her mother's side of the family and is delighted to find that she has Swedish heritage.

Michelle Keegan uncovers some exceptional women on her family tree, including a special connection to the suffragettes.

Michelle Keegan uncovers some exceptional women on her family tree, including a special connection to the suffragettes.

Oscar-winning actress Olivia Colman travels to India to find out more about her great-great-great-grandmother.

Oscar-winning actress Olivia Colman travels to India to find out more about her great-great-great-grandmother.

Comedian Lee Mack finds out more about his great-grandfather, who was also a comedian, known as Billy Mac.

Comedian Lee Mack finds out more about his great-grandfather, who was also a comedian, known as Billy Mac.

Boy George expects to find sadness in his family tree, but delights in a new sense of his family being part of Irish history.

Boy George expects to find sadness in his family tree, but delights in a new sense of his family being part of Irish history.

Shirley Ballas investigates her great-grandmother who abandoned her husband and children for a more exciting life in America.

Shirley Ballas investigates her great-grandmother who abandoned her husband and children for a more exciting life in America.

Michelle Keegan uncovers some exceptional women on her family tree, including a special connection to the suffragettes.

Oscar-winning actress Olivia Colman travels to India to find out more about her great-great-great-grandmother.

Comedian Lee Mack finds out more about his great-grandfather, who was also a comedian, known as Billy Mac.

Boy George expects to find sadness in his family tree, but delights in a new sense of his family being part of Irish history.

Shirley Ballas investigates her great-grandmother who abandoned her husband and children for a more exciting life in America.

Doctor Who actor Jodie Whittaker finds out how her great-great-grandfather worked his way up from child labourer in a Yorkshire coal mine to mine owner.

Doctor Who actor Jodie Whittaker finds out how her great-great-grandfather worked his way up from child labourer in a Yorkshire coal mine to mine owner.

Marvin Humes looks at his Jamaican and his English heritage, finding exceptional stories on both sides of the family.

Marvin Humes looks at his Jamaican and his English heritage, finding exceptional stories on both sides of the family.

Robert 'Judge' Rinder investigates his grandfather, a Holocaust survivor, and the dark mystery surrounding his great-grandfather.

Robert 'Judge' Rinder investigates his grandfather, a Holocaust survivor, and the dark mystery surrounding his great-grandfather.

Paralympian Jonnie Peacock looks back through the generations and ends up captivated by his four-times-great-grandmother.

Paralympian Jonnie Peacock looks back through the generations and ends up captivated by his four-times-great-grandmother.

Actor Daniel Radcliffe discovers that the Hatton Garden robbery of his great-grandfather's jewellery business was far more dark and dramatic than he ever imagined.

Actor Daniel Radcliffe discovers that the Hatton Garden robbery of his great-grandfather's jewellery business was far more dark and dramatic than he ever imagined.

Actor Naomie Harris's dramatic discoveries in this episode inspire her to anger, sadness and tears of joy.

Actor Naomie Harris's dramatic discoveries in this episode inspire her to anger, sadness and tears of joy.