Who Do You Think You Are? Season 15 Episode release dates & where to watch

1. Michelle Keegan

Our Girl actress Michelle Keegan uncovers some exceptional women on her family tree. On her mother's side Michelle discovers that her Gibraltarian great-grandmother Leonor had to up sticks when all women and children and the elderly were evacuated from harm's way in Gibraltar to the apparent safety of London during the Second World War, a month before the start of the Blitz.Further back, Michelle discovers her great-great-grandmother Elizabeth Kirwan living in poverty in Manchester at the start of the 20th century. Michelle unearths a special connection to suffragette Emmeline Pankhurst and her great-great-grandmother's commitment to the cause that put her name on the electoral roll - voting for the very first time in 1918.

2. Olivia Colman

Actress Olivia Colman claims to be 'the least adventurous person I know.' As for her ancestors, apart from a rumour that there was a Frenchwoman somewhere in her family tree, Olivia thinks they are largely from Norfolk, so she is astonished to discover that she needs to travel to India to find out more about her great-great-great-grandmother Harriot. Olivia finds records that reveal Harriot was an orphan in 1811 on a ship bound for England from (then) Calcutta. Harriot's father was an Englishman, but the identity of her mother, who gave birth to her in a remote Indian village, is a mystery Olivia delights in solving.

3. Lee Mack

Comedian Lee Mack was born Lee McKillop in the north of England, just like his McKillop great-grandfather, who was also a comedian, known as Billy Mac. Lee has a few playbills from Billy Mac's variety hall performances, but knows little more about him. Not long into his journey, Lee discovers that his great-grandfather was passionate about more than making people laugh. Billy Mac joined the first ever pals battalion in Liverpool at the start of the First World War and honed his act at the front lines in the Battle of the Somme. Lee is also curious about his maternal grandad Joe's upbringing - deserted by his unwed mother and raised by his grandparents in County Mayo at the time of the Irish Civil War.

4. Boy George

Iconic pop star Boy George grew up in south London in an Irish family. George expects to find a lot of sadness in his family tree. He knows that his maternal grandmother was found wandering the streets of Dublin as a small child and put in a children's home and wants to find out how she came to be in such a dire situation. He's also heard that another ancestor was hanged in Dublin's Mountjoy Gaol and is somehow connected to Kevin Barry who was commemorated in a well-known Irish rebel song. As George uncovers the grim details of what really happened to his grandmother and his great uncle, he also delights in a new sense of his family being truly part of Irish history.

5. Shirley Ballas

Strictly Come Dancing's head judge Shirley Ballas investigates a family story that her maternal great-grandmother abandoned her husband and children for a more exciting life in America. What Shirley discovers casts her great-grandmother in a completely new light. On her father's side, Shirley pursues a rumour that she has black ancestors - a trail which leads her to colonial Cape Town and the era of slave trafficking to South Africa via the Indian Ocean.

6. Marvin Humes

DJ, presenter and former member of boy band JLS, Marvin Humes delves into his Jamaican and his English heritage, and finds exceptional stories on both sides of the family. Deep in the Jamaican countryside, Marvin's discoveries about the lives of his black ancestors during the time of slavery turn his expectations upside down. In England, Marvin's follows the trail of his great-grandfather about whom he knows almost nothing. But Marvin's research reveals a hero, who overcame a traumatic childhood to play a part in one of the most dramatic events of the Second World War.

7. Robert Rinder

Robert 'Judge' Rinder follows the story of his grandfather, a Holocaust survivor, hearing first-hand testimony of the horror of Nazi forced labour camps as well as of the hope offered by a new life in Lake Windermere. Investigating the dark mystery surrounding his great-grandfather leads Robert to a small town in Latvia, where he uncovers a story of mental illness and trauma which will ultimately, he hopes, lay some ghosts to rest.

8. Jonnie Peacock Finale

Paralympic gold medal winner Jonnie Peacock was named for his maternal grandad, who died the year before he was born. Like Jonnie, his grandad was a sportsman - an excellent amateur footballer scouted by a professional team, only to be thwarted by parental pressure to take a 'proper job' as a painter/decorator. Pushing back down the generations, Jonnie uncovers the legacy of poverty and unexpected disease that led the family to value job security over the beautiful game. On his father's side, Jonnie is captivated by his four-times-great-grandmother, branded a 'bad character' in 1841 by a local village policeman. But Jonnie's further research reveals a strong woman prepared to stand up in court and testify against the men who had wronged her.