Wallace Brian Vaughan Sinclair MRCVS (27 September 1915 – 13 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 semi-autobiographical 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 re-take examinations because of his lack of application, often found in the pub, and provoking tirades from his bombastic elder brother Siegfried.