Anne Chapman's story in All Creatures Christmas special was inspired by guest star Cleo Sylvestre's own family history

But the team behind the Channel 5 adaptation of the drama came across Cleo's writings about her own family history in Yorkshire – and decided to weave elements of that story into the script.

Cleo tells RadioTimes.com: "My mother was born in Yorkshire to a Yorkshire mum, and we don't know the dad, and so – shock horror! Because the mum was white and the baby came out a different colour. And that was in 1911, so it was a big, big scandal. So she was put in a home, she was brought up in a children's home."

Laureen grew up in care and was soon employed in service, then in a kitchen, and then in a dance troupe. She moved to London and in 1944 she married Owen Oscar Sylvestre, an immigrant from Trinidad; Cleo was born in 1945. Many years later, Cleo discovered that her biological father was actually a lawyer from Sierra Leone.

Cleo decided to find out more about her mother's early life, writing a profile on the website Africans in Yorkshire. She reflected: "I began to discover what it must have been like to grow up as a mixed-race, illegitimate child in a Yorkshire village during the early part of the last century. I also began to reconsider the history of Black people in Britain."

All Creatures director Andy Hay came across Cleo's article while doing his research for the show – and that's where it all began.

Executive producer Colin Callender says: "Andy Hay went out and began casting the role of Anne and he fell in love with Cleo Sylvestre, who was Black, and through conversations with her about her own story and her own mother's story, that story found its way into the script. And Ben [Vanstone, the writer], took Cleo's real story and wove it seamlessly into the episode. So there's a very nice sort of example there of fiction really reflecting the real world."

Callender, who recently hit out at claims that All Creatures was rejected by the BBC for not being 'woke enough', added: "Being able to cast truthfully but embracing diversity, whether it's diversity in terms of the role of women, disabled people, and as we go forward in season two, Black stories and Black actors, that will all be part of our agenda as we go forward. But this episode was a particular joy."

In the episode, James Herriot (Nicholas Ralph) is called up to the Chapmans' remote cottage on Christmas Eve when their pregnant dog gets into difficulty. Although she's getting married the next morning, Helen Alderson (Rachel Shenton) decides to go with him to get away from the wedding fuss.

Picking up on James's feelings for Helen and the chemistry between them, Anne – described by Cleo as "canny Anne" – tells the story of her own 40-year marriage and dispenses some words of wisdom. "We didn't have a crowd of folk like you will when we got married," she says. "Weren't many round here wanted to see a Yorkshireman marry a woman that looked like me. But you can't help who you fall in love with."

Anne adds: "I were working in service at the farmhouse. Bert came to work as a hand. Both of us tried to fight it. We knew it would cost our jobs, our friends. It were worse for Bert, of course. I was already an outsider. By rights, Bert should have wanted nowt to do with me. But love don't see with the eyes. It comes from in here. In the end, there's no fighting it."

As for how Cleo expects people to react when they see the Christmas episode, she tells us: "I think people will be very surprised, actually! And they might actually think it's been put in because of what's been happening in the last few months with Black Lives Matter and everything. But in fact this was filmed way before then.

"And also, it is true... there were people in Yorkshire at that time, people of colour. There was a big community, and also in other places like Liverpool and Bristol. So there were people of colour, Black people, there. But they just haven't been remembered because people always think that Windrush was the time that Black people started to be present over here. But in fact it's not true."

Of course, the Chapmans (and their dog) now exist within the world of All Creatures Great and Small. So would Cleo be up for returning to the show?

"I'd love to," she says. "I'd love to. And working with Dave Hill is such fun, because I knew Dave anyway and he's from there. And it was lovely. So it would be great if we could go back."

The All Creatures Great and Small Christmas special will air on 22nd December 2020 at 9pm on Channel 5. While you're waiting, take a look at our TV guide to find out what's on this week.