James Herriot was the pen name of James Alfred Wight, known as Alf. He was born in Sunderland in 1916, grew up in Glasgow and trained there as a vet. After qualifying in 1939 he moved to Thirsk, North Yorkshire, to work in the Kirkgate practice of Donald Sinclair, the real man behind Siegfried Farnon in the books. He wrote under an invented name because the profession's rules discouraged vets from advertising themselves. He was past fifty when his first book came out, and he died in 1995.
His books are semi-autobiographical: short, episodic stories of farm calls, difficult animals, eccentric clients and an unpredictable senior partner. They are drawn from his working life but shaped for the page, with characters and timelines adjusted. The tone is conversational and comic, with sudden stretches of tenderness, and the subject is a way of rural life that was already changing.
If Only They Could Talk appeared in 1970 from Michael Joseph and sold slowly. A New York publisher then combined his first two books under the title All Creatures Great and Small, and the series took off. Britannica reports about 80 million copies sold and 36 languages. Adaptations include a 1975 film, the BBC series that ran from 1978 to 1990, and a Channel 5 series that began in 2020. His former home and surgery in Thirsk is now a museum.
Start with All Creatures Great and Small, the book listed here. In the best-known edition it gathers the first two volumes, so you meet Herriot, Siegfried and the Dales in one go. If you want more afterwards, All Things Bright and Beautiful continues the story, and Every Living Thing, from 1992, comes late in the sequence.