Meet the cast of BBC divorce drama The Split

Six-part drama The Split tells the story of the Defoe family – and what happens after leading divorce lawyer Hannah leaves the family firm. She now faces her sister Nina and mother Ruth on the opposing side of high-profile divorce cases. On top of that, her father has returned after 30 years without a word of explanation.

Here are all the characters you need to meet – and where you've seen the actors before:

Nicola Walker plays Hannah Sterne

Who is Hannah? Talented divorce lawyer Hannah Sterne recently left the Defoe family law firm to join their rivals at Noble & Hale. To say the least, this has strained her relationship with her single mother Ruth and her sisters Nina and Rose. Hannah has three kids with her husband, Nathan – who is also a lawyer.

What else has Nicola Walker been in? We recently saw Nicola as gay vicar Jane Oliver in Collateral. She also stars as DCI Cassie Stuart in Unforgotten, and plays Gillian in Last Tango in Halifax – a role which earned her a Bafta nomination. You may also remember Nicola from spy drama Spooks, where she played Ruth Evershed.

Stephen Mangan plays Nathan Sterne

Who is Nathan? Hannah's husband Nathan is also a lawyer. He is friendly and charming and gets on well with her family.

What else has Stephen Mangan been in? Stephen starred as Guy Secretan in hospital comedy Green Wing, as Dan Moody in I'm Alan Partridge, and as Dirk Gently in Dirk Gently. He later teamed up with his Green Wing co-star Tamsin Greig for the TV series Episodes.

Barry Atsma plays Christie

Who is Christie? Hannah's colleague at Noble & Hale, the law firm she has just joined. The two share some kind of romantic history.

What else has Barry Atsma been in? Dutch actor Barry Atsma rose to fame in Holland in the TV series Rozengeur & Wodka Lime. Since then he has appeared in Bad Banks, Klem, The Hitman's Bodyguard, Black Widow, and Stephen Mangan comedy drama Episodes – as Arjen Van Der Linden.

Deborah Findlay plays Ruth Defoe

Who is Ruth? The first time we meet her, it's Ruth's 70th birthday. As the head of a family of female divorce lawyers, Ruth has her own firm and raised her three daughters all by herself after her husband walked out when they were children, never to be seen again. Until now.

What else has Deborah Findlay been in? Recently we saw Deborah as Sandrine's cold, distant, grief-stricken mother Eleanor Shaw in the TV series Collateral. Over the last few years she's appeared in Jackie, The Lady in the Van, and Hampstead.

Annabel Scholey plays Nina Defoe

Who is Nina? Hannah's younger sister Nina works at the Defoe family law firm. She's talented, tough, and flirtatious.

What else has Annabel Scholey been in? Recent roles have included Amena in Britannia, Contessina in Medici: Masters of Florence, and Gemma Nunn in Inspector George Gently.

Fiona Button plays Rose Defoe

Who is Rose? The youngest of Ruth's three daughters and the only one who's not a divorce lawyer – instead she's currently working as a nanny and figuring out what she wants from life. Rose is engaged to be married to James (Rudi Dharmalingam).

What else has Fiona Button been in? Fiona's CV includes roles in Grantchester, My Mother and Other Strangers, You Me and the Apocalypse, and Lip Service.

Anthony Head plays Oscar

Who is Oscar? Hannah, Nina and Rose's long-lost dad. He walked out of the family home 30 years ago and never returned, but now he's back on the scene - tracking eldest daughter Hannah down in the park to hand over a 70th birthday card for Ruth. But why has he returned after so long and what does he want?

What else has Anthony Head been in? Remember Rupert Giles in Buffy the Vampire Slayer? That was Anthony. He's also known for his roles as Uther Pendragon in Merlin, the Prime Minister in Little Britain, and John in Girlfriends. He'll next be seen on screen in the TV mini-series Vanity Fair, as Lord Steyne.