Of the 60 Holmes stories written by Doyle, 43 were adapted in the series, spanning 36 one-hour episodes and five feature-length specials.

His practice is largely with private clients, but he is also known to assist the police, often in the shape of Inspector Lestrade, when their cases overlap.

His ability to spot clues easily overlooked by others, bring certain specialist knowledge — for example chemistry, botany, anatomy – and deductive reasoning to bear on problems enable him to solve the most complex cases.

Holmes craves mental stimulation, and is known to relapse into depression, and drug use when there are no sufficiently complex cases to engage him.

Kenneth Connor made his last filmed appearance in "The Red Circle" as Mr Warren, which was broadcast posthumously in 1994, a year after his death.

It was developed for television by screenwriter John Hawkesworth, who also wrote many of the episodes (all based on individual Doyle stories).

Other writers to adapt Doyle's short stories in the series included Alexander Baron, Jeremy Paul, T. R. Bowen, and Alan Plater.

[10] He had suffered from ill health during filming of the later series due to adverse reactions to the medicine prescribed for depression.

Though the Granada series is one of the most comprehensive screen adaptations of the Holmes canon,[a] it nevertheless left 19 stories unadapted after Brett's death.

As well as being broadcast by ITV in the UK, the series was also seen overseas, particularly in the United States, where the episodes initially ran on PBS stations in the Mystery!

In March 2006, the series returned to its original channel for the first time in over a decade, as part of the daytime television line-up on weekday afternoons.

[16] Nonetheless, the series has been highly praised for the performance of Brett, its adherence to Doyle's original concept in the characterization of Watson as a young, slim, capable man of action in defiance of the stereotype set by Nigel Bruce, its high production values, and its close attention to period detail.