- "There are many men in London, you know, who, some from shyness, some from misanthropy, have no wish for the company of their fellows. Yet they are not averse to comfortable chairs and the latest periodicals. It is for the convenience of these that the Diogenes Club was started, and it now contains the most unsociable and unclubable men in town. No member is permitted to take the least notice of any other one. Save in the Stranger's Room, no talking is, under any circumstances, allowed, and three offences, if brought to the notice of the committee, render the talker liable to expulsion. My brother was one of the founders, and I have myself found it a very soothing atmosphere."
- ―Sherlock Holmes [src]
The Diogenes Club was a private establishment that required absolute silence at all times, unless one was in "the Stranger's Room". Mycroft Holmes was one of the founders of the club and spent a lot of his time there, presumably to allow him to think undistracted.
The Canon Sherlock Holmes stories
The Diogenes Club appears in several stories, including "The Adventure of the Greek Interpreter".
Main article: Diogenes Club (Granada)
The club's first and most prominent appearance in the series occurs in the episode "The Greek Interpreter", adapting the eponymous original story. This episode also features the first appearance of Mycroft Holmes.
- "Three quarters of the diplomatic service and half the government front bench all sharing one tea trolley, it's for the best, believe me. We don't want a repeat of...1972."
- ―Mycroft Holmes, "The Reichenbach Fall".
Mycroft Holmes was a member and Dr John Watson visited the club at his request in "The Reichenbach Fall". Of course, being John, he didn't understand the rules of silence and had to be promptly removed out of the main sitting room to Mycroft. He was also seen sitting in the same club during "The Hounds of Baskerville" when he receives the security alert that Sherlock is using his security access to break into the Baskerville Military Base. A Victorian Era version is also shown in 'The Abominable Bride'.
- In the American tv series Elementary, Diogenes is the name of multiple restaurants owned by Mycroft Holmes