Wallace Brian Vaughan Sinclair (27 September 191513 December 1988) was a British veterinary surgeon who worked for a time with his older brother Donald, and Donald's business partner, Alf Wight. Wight wrote a series of semiautobiographical novels under the pen name James Herriot, with Sinclair and Donald appearing in fictionalised form as brothers Tristan and Siegfried Farnon. The novels were adapted in two films and television series under the name All Creatures Great and Small. Tristan was portrayed as a charming rogue who was still studying veterinary medicine in the early books, constantly having to retake examinations because of his lack of application, often found in the pub, and provoking tirades from his bombastic elder brother Siegfried. Sinclair studied veterinary medicine at the Royal Veterinary College in Edinburgh. He graduated in 1943 and returned to his brother's practice at 23 Kirkgate in Thirsk, Yorkshire. In the following year, he enlisted in the Royal Army Veterinary Corps and married Sheila Rose, the only daughter of Douglas Seaton, a general practitioner based in Leeds. Shortly after his marriage, he was deployed to Haryana in India, and on demobilisation, he joined the Ministry of Agriculture's Sterility Advisory unit in Inverness, Scotland. In 1950, the ministry offered him a transfer to the Veterinary Investigation Centre in Weetwood Lane, Leeds, a diagnostic laboratory for veterinarians in Yorkshire. Sinclair retired in 1977 after he had risen to become head of the investigation centre. In retirement, he gave talks on Herriot and Yorkshire, and spoke at veterinary schools in the United Kingdom and the United States. When Wight's first book was published, he was delighted to be captured as Tristan and remained enthusiastic about all Wight's books. He seemed to enjoy being a celebrity and would host informal evenings for tourist groups visiting "Herriot country". He was due to appear as the lead speaker at the annual meeting of the New York State Veterinary Medical Society but he died at Leeds General Infirmary before the meeting could take place. Early life and education Sinclair was born at Harrogate on 27September 1915. His father, James, was the son of a crofter who had moved from the Isle of Sanday in the late 19th century. James was said to have been a leather manufacturer but died when Sinclair was just two years old. Sinclair's elder sister, Elsa Vaughan, married Cyril Walter Russell on 5 June 1934 at St Robert's