Bafta award winning actress Olivia Colman features in the latest episode of the BBC's Who Do You Think You Are? and discovers some surprises in her ancestral history.

A belief that most of those in her family tree emanate from Norfolk turns out to be far from the truth.

'I don't know what's happened in my family, and I don't know who's been forgotten... and it might be quite nice to remember them again,' she explains.

Olivia is amazed to discover that she needs to travel to India to find out more about her great-great-great grandmother Harriot, who was an orphan in 1811 on a ship bound for England from 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.

The Norwich-born thespian's own history is more well-documented than any of her family's.

She caught the acting bug in a school version of The Prime of Miss Jean Brodie. While studying teaching in Cambridge, she honed her acting skills at Bristol Old Vic Theatre School.

By 1999, Olivia graduated, and while at Cambridge University Footlights Dramatic Club, she met fellow rising stars David Mitchell and Robert Webb.

It marked the beginning of many collaborations. Radio show That Mitchell and Webb Sound naturally paved the way for TV hit That Mitchell and Webb Look, while appearances in their hit sitcom Peep Show also kept the wolf from the door.

She came to many peoples' attention in surreal medical comedy Green Wing. Roles in TV hits Beautiful People and Skins didn't hurt either, while her turn as a licentious copper in Hot Fuzz ensured she'd become an ITV2 staple for years.

However, it was as crime buster Ellie Miller that her status as national treasure was affirmed. Three series of Broadchurch left millions perched on the edge of their seat.

Naturally Olivia has plenty of irons in many fires at the moment. She's playing Madame Thenardier in a TV version of Les Miserables; will portray Queen Anne in The Favourite (in which she re-teams with Yorgos Lanthimos, director of The Lobster), and will take over as Queen Elizabeth II in TV smash The Crown.

The latter has already won a Golden Globe for Claire Foy in the same role, and there's a good bet Ms Colman will also be in the running in a year or so.

If so she can add it to the one she won for The Night Manager; the Baftas she won for Twenty Twelve, and Accused, and the assorted other gongs weighing down her shelves.

'I'm interested in the people that have gone before,' she explains in WDYTYA. 'There's a fragility to life, and also when you go, will you be forgotten?

• Who Do You Think You Are? BBC One, Monday July 9, 9pm.