The children of All Creatures Great and Small author James Herriot tell of the wonderful Yorkshire Dales world he captured for posterity

At 23, he could not have known how long he would stay, and how closely associated he and his new home would become, in reality, in fiction and on screen, now forever known and entwined as James Herriot and Darrowby. Nor could he have known that he would capture for posterity a world that would soon be gone.

“I feel very nostalgic when I drive round and see where little farms used to be,” says Jim Wight, Alf’s son, who worked alongside his father at the Thirsk veterinary practice for 25 years. “It’s very sad, and I am so pleased that Dad has written these books, because they have preserved that way of life that we all knew. When I started, a man milking 20 cows could make a good living. Now you have got to milk 200, and hardly break even.

“Nowadays, the farms that are there are full of machinery. In my day they were full of men. A lot of these men were characters in their own right.”

Jim and his sister, Rosie Page, have worked together with editor Emma Marriott on a new book called The Wonderful World of James Herriot, a collection of favourite stories taken from all eight of the vet novels, interwoven with background and insight as to what happened in real life to inspire the penned work.

James Herriot the author was a late bloomer. His first book, If Only They Could Talk, was published in April 1970 when Alf was 54.

“He had no idea that he was going to carry on writing,” says Rosie. Alf had been considering writing a novel based on his vetting experiences for years. Encouraged by his wife, Joan, he finally wrote one and sent it off to Collins, who turned it down, but a professional reader called Juliana Wadham suggested he try rewriting it in the first person, as a semi-autobiographical work.

Wise advice indeed, because Michael Joseph accepted it. Alf picked the pen name James Herriot using his real first name and that of future Scotland goalkeeper, Jim Herriot. There were other deviations to preserve anonymity, setting it in 1937, pre-war, and locating it, and the subsequent seven novels, rather more generically in the Yorkshire Dales.

Both Rosie and Jim still live in and around Thirsk, with “roots as deep as you like”, Rosie says. Her father’s stories still make her laugh and lift her up. “He was a genius with words,” she says.

Jim says: “It’s the interplay that I think is so funny between Siegfried and his younger brother. They are one of the great comedy duos to me - the love-hate relationship.”

Siegfried and Tristan were based on Alf’s real-life fellow vets Donald Sinclair and younger brother Brian, who were a constant presence in Rosie and Jim’s young life. They called Donald and his wife “Uncle Donald and Auntie Audrey”, a fact that will excite many fans of Channel 5’s remake of All Creatures Great and Small. Some might also be surprised to learn that Donald was just five years older than Alf and Brian.

Jim says: “My father told me, many years ago, when the three of them were knocking about in the big house there, Donald was frying three eggs for breakfast, one each, and as my father and Brian walked in, Donald turned to his younger brother and said: ‘Your egg’s broken.’ That was typical. And yet, when Brian died, I remember going to see Donald at his house up in the hills here in Thirlby, and gave my condolences, and Donald just wept. He really thought a lot about him, of course.

Donald, says Jim, had “no awareness of his amazingly eccentric personality” and was appalled by his portrayal. “‘Alfred – he always called him by his full name, never Alf - ‘this book is a test of our friendship’. Yet, when tourists from America came to our little surgery, he would show them round and give them guided tours.”

Jim has a treasured possession, a first edition of If Only They Could Talk, inscribed by Donald. “It says ‘To Alfred, with best wishes from Donald’. Alfred wrote the bloody thing.”

Jim and Rosie helped their father on his rounds, so naturally wanted to follow in his path. Sure enough, Jim went to Glasgow University and became a vet at the same practice. Some of the Herriot stories were in reality inspired by his experiences.

But Alf was less keen that Rosie follow suit, and she studied Medicine at Cambridge. “I am glad I became a doctor rather than a vet,” she says. “I wanted to do what he did, go round farms, and he didn’t want me lying on my stomach in a cow byre. He gradually put me off, and I have never had any regrets.”

She worked as GP in Thirsk for 20 years, and she and Jim had many patients in common. “You find in life that there are people who are awkward, whoever they are going to,” she says. “I thoroughly enjoyed being a GP.”

The immortal Mrs Pumphrey and Tricki Woo were based on a Miss Warner and Bambi, Rosie and Jim well remember the hampers sent to Uncle Wight. “He was not sending her up,” Rosie says. “He was extremely fond of Bambi and Miss Warner – another heaven-sent character for him to write about.”

Their father enjoyed the BBC TV series of All Creatures Great and Small, not least because it stuck closely to his dialogue. Rosie says: “He got a big kick, particularly with Robert Hardy, who by then was already one of our most esteemed actors, hearing him saying the words he had written.” They approve of and enjoy the Channel 5 series, too. “The acting and the production – top notch,” says Rosie. “Top notch,” agrees Jim. Rosie says: “It was particularly surreal to see our mum and dad get married,” adding that Joan did not wear a white dress (it was war-time, after all) as Helen, played by Rachel Shenton, does in the recent on-screen nuptials. Jim points out that, although some viewers questioned the otherwise low-key nature of the TV wedding, with just a few guests in the church, the real one was actually much smaller. “In reality, there were five people - Mum and Dad, Donald Sinclair (best man), someone to give mum away, and the vicar. Neither set of parents. They spent their honeymoon tuberculin testing up in the Yorkshire Dales”

Joan was a secretary rather than a farmer’s daughter, but the courtship as written in the books is based on real life, although the portrayals of their relationship and Helen’s character have been developed on screen for a modern TV audience. Rachel has occasionally been emailing Rosie to ask for small details. “Dad doesn’t give as much away about Mum and the sort of person that she was,” Rosie says. “She will ask me little things, like did they use endearments like ‘darling’ and ‘dear? We both laughed, because they certainly didn’t.”

Although, Rosie recalls, in later life, she would drive them back from seeing their beloved Sunderland Football Club, and there they would be, on the back seat, fast asleep, holding hands. They both enjoy the statue of their father that now stands at World of James Herriot, the museum housed in the old Thirsk veterinary practice that was their first home. Rosie says: “It is standing in the long, thin garden where he lived and worked, and to me, it almost looks like a shrine, and that stance that he has got, that Sean Hedges-Quinn has achieved, is absolutely him.”

The Wonderful World of James Herriot is published by Macmillan at £22. Rosie Page and Jim Wight will be taking part in An Evening of Celebration of James Herriot at Harrogate Library on Wednesday, November 2, 7.30pm, tickets £5 from Imagined Things Bookshop in Harrogate, and www.imaginedthings.co.uk. They will also be signing the book on Friday, November 4, 11am to 1pm, at World of James Herriot in Thirsk.