Helena Bonham Carter has said digging into her family history for a Channel 4 show convinced her that researching your grandparents should be part of the national curriculum.

Bonham Carter, 53, who is starring as Princess Margaret in The Crown, is one of four actors and actresses exploring their grandparents’ wartime stories in a series for Channel 4.

Sir Mark Rylance, Kristin Scott Thomas and Carey Mulligan also appear in their own episodes of My Grandparents’ War.

Mark Rylance quits the RSC
Sir Mark Rylance (Ian West/PA)

Bonham Carter said she had become “evangelical” about digging into her past since appearing on the show, which commemorates the 80th anniversary of the start of the Second World War.

Her maternal grandfather Eduardo Propper de Callejon was a Spanish diplomat who defied his government’s orders and helped Jews escape the Holocaust during the Nazi invasion of France.

She also learned that her English paternal grandmother Lady Violet Bonham Carter, a mother of four and liberal politician, also fought anti-Semitism as a volunteer air raid warden.

Bonham Carter said: “It’s a great family. And I’m proud now to be able to share it.

“Part of me feels like this was just the beginning because this whole thing was a gift for me… we were given a chance to go and explore and ask the questions and hear what really happened, and then have extraordinary surprises – the level of research, and the people that did the research, they were extraordinary in what they managed to dig up.

BAFTA Film Awards 2018 – Arrivals – London
Kristin Scott Thomas (Yui Mok/PA)

“For me, my family is extraordinary, and I was born too late and they died too soon, so for me it was like I met them properly, and had a conversation with them, and I also want to carry on conversing with my mum. The conversations that I’ve started, I feel like there’s a lot more, and one thing that I have gone around, because I’m almost evangelical, is saying that it’s one of the most important things I’ve done.

“I feel like every young person should go and interview their grandparents.”

The programme also sees Bonham Carter interview her grandmother, called Bubbles, at length.

She said: “I did, years ago, interview my mother’s mother for hours because, just like you (Scott Thomas) said, your mother was very chatty.

“All the women in our family never really do stop talking, and I’ve got hours of Bubbles, and she is actually in the documentary, but I do feel it should be part of the national curriculum, we should have all our grandchildren – well, not my grandchildren, I always age myself up – but my children, I want them to talk to my parents and there should be this handing down.

“And also what struck me watching that is that there is all this silence around trauma, so it needs time for people to make sense of it

“We were lucky – it’s the time for people to speak and for us to find out. The whole thing was extraordinary, and I hope that you find it as stimulating as I did.”

My Grandparents’ War starts on Channel 4 on Wednesday November 27.