This series was largely adapted from a collection of then obscure, but genuine Victorian short stories collated and edited by Hugh Greene, who is also credited as the series creator. He was a retired Director General of the BBC and the brother of Graham Greene.
Thames Television released a set of thirteen stories that aired on British television weekly from September to December 1971. It proved to be so popular that a second set of thirteen stories was produced and aired from January to April 1973.
Douglas Wilmer (Professor Augustus S. F. X. Van Dusen), Peter Barkworth (Martin Hewitt), Peter Vaughan (Horace Dorrington), Ronald Hines (Jonathan Pryde), Kenneth Colley (Farrish) and Petronella Barker (Miss Parrot) are the only actors to play the same character in more than one episode. However, the characters of Dr. John Thorndyke and his sidekick Dr. Jervis appeared in two episodes (played by different actors).
John Neville, Robert Stephens, and Douglas Wilmer all previously played Sherlock Holmes and Charles Gray would go on to play Mycroft Holmes in the movies and on TV.
Barrie Ingham(Dr. Thorndyke) would go on to provide the voice of Basil of Baker Street in Disney's The Great Mouse Detective(1986), which was inspired by Sherlock Holmes.