But where did the inspiration for such a complex character come from? If you think that such extraordinary powers of deduction couldn't possibly couldn't possibly be real, you might be surprised.
A physician and lecturer at the University of Edinburgh, Dr Joseph Bell came from strong family of doctors. He was also renowned for his acute attention to detail and eccentricity. Sound familiar?
Arthur Conan Doyle met Bell in 1877 as one of his medical school students. The would-be author also went on to be the professor's clerk -- a relationship that is reminiscent of Holmes and Watson.
Bell seems to have treated the practice of medicine as a kind of investigation. In a piece written for the Strand Magazine (where Conan Doyle's first Sherlock Holmes short stories were published), Bell stated:
"In teaching the treatment of disease and accident all careful teachers have first to show the student how to recognize accurately the case. The recognition depends in great measure on the accurate and rapid appreciation of small points in which the diseased differs from the healthy state. In fact, the student must be taught to observe.
To interest him in this kind of work we teachers find it useful to show the student how much a trained use of the observation can discover in ordinary matters such as the previous history, nationality and occupation of a patient."
Conan Doyle freely admitted throughout his life that Bell was the primary inspiration behind his infamous detective, stating in a letter, "round the centre of deduction and inference and observation which I have heard you inculcate I have tried to build up a man."
A stickler for detail, Bell could apparently pick a person's profession by paying attention to their clothing, the objects in their possession and even their speech patterns.
In Conan Doyle's autobiography, he recounted one such incident between his mentor and a patient.
"Well, my man," Bell said, after a quick glance at the patient, "you've served in the army."
"Aye, sir," the patient replied.
"Not long discharged?"
"A Highland regiment?"
"A non-com officer?"
"Stationed at Barbados?"
Bell turned to his bewildered students. "You see, gentlemen," he explained, "the man was a respectful man but did not remove his hat. They do not in the army, but he would have learned civilians ways had he been long discharged. He has an air of authority and he is obviously Scottish. As to Barbados, his complaint is elephantiasis, which is West Indian and not British, and the Scottish regiments are at present in that particular island."
The idea of creating a fictional detective from Bell's mannerisms may have also been inspired by his police links. The professor was one of the first doctors to specialise in forensic pathology during the 19th century.
In fact, his expertise was so well regarded that he was involved in several high profile police investigations. He even provided Scotland Yard with his own personal analysis of the Jack the Ripper Murders.
In 2011 the Japan Sherlock Holmes Club erected a plaque in Edinburgh to mark the centenary of Bell's death -- further solidifying his importance to fans of Sir Arthur Conan Doyle and his infamous detective.