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This article is for Sir Arthur Conan Doyle's character. For other versions of the character see Versions of Mycroft Holmes.

Mycroft Holmes is the older brother of Sherlock Holmes. He possesses even greater powers of observation and deduction compared to his younger brother; however, he lacks the energy and inclination to use them in the same way as his brother.


"...he has no ambition and no energy. He will not even go out of his way to verify his own solutions, and would rather be considered wrong than take the trouble to prove himself right. Again and again I have taken a problem to him, and have received an explanation which has afterwards proved to be the correct one. And yet he was absolutely incapable of working out the practical points..."
―Sherlock Holmes, speaking to Watson about his brother in "The Adventure of the Greek Interpreter"

Mycroft Holmes possessed greater powers of deductive reasoning compared to his brother, Sherlock Holmes. Sherlock even stated that Mycroft possessed in a larger degree a faculty of observation and peculiar facility for deduction than himself. He was unwilling, however, to put physical effort behind these powers. It was implied that he lacked practicality and completely dispassionate. Mycroft occupied an unspecified role in the British government. His brother stated that Mycroft audited books for certain government departments; however, his true role was hinted as to be more substantial and influential. ("The Adventure of the Greek Interpreter")

Mycroft also spent large amounts of time at the Diogenes Club and was seven years older than Sherlock.


"He has the tidiest and most orderly brain, with the greatest capacity for storing facts, of any man living. The same great powers which I have turned to the detection of crime he has used for this particular business. The conclusions of every department are passed to him, and he is the central exchange, the clearinghouse, which makes out the balance. All other men are specialists, but his specialism is omniscience. We will suppose that a minister needs information as to a point which involves the Navy, India, Canada and the bimetallic question; he could get his separate advices from various departments upon each, but only Mycroft can focus them all, and say offhand how each factor would affect the other. They began by using him as a short-cut, a convenience; now he has made himself an essential. In that great brain of his everything is pigeon-holed and can be handed out in an instant."
―Sherlock Holmes, speaking to Watson about his brother in "The Adventure of the Bruce-Partington Plans"

It has been stated that Mycroft Holmes possessed greater powers of observation and deductive reasoning, compared to his brother, Sherlock Holmes. Mycroft's mind has unlimited storage and analytical capacity, he is able to instantly recall any information he has with perfect clarity. The speed of his thoughts allows him to analyze his surroundings for information in an instant; noticing, processing and understanding all the details of any situation or environment, no matter how small. He instantly cross-correlates all information he has, allowing him to flawlessly find and analyze patterns, understand the mechanics behind anything, and deduce an optimal solution. He uses this information to track the probability of an event by piecing together stored and acquired data. This allows him to identify all the variables in any situation and use this information to automatically adjust the outcome so it is the most optimal outcome possible for him. Hence, why the conclusions of every department are passed to him; he takes fractured, seemingly unrelated information and connects it, serving as a sort of human computer.


Mycroft Holmes was a much larger and stouter man than Sherlock. His body was absolutely corpulent, but his face, though massive, had preserved something of the sharpness of expression which was so remarkable in that of his brother. His eyes, which were of a peculiarly light, watery gray, seemed to always retain that far-away, introspective look which Sherlock only possessed when he was exerting his full powers ("The Greek Interpreter"). He had a head so masterful in its brow, so alert in its steel-grey, deep-set eyes, so firm in its lips, and so subtle in its play of expression, that after the first glance one forgot the gross body and remembered only the dominant mind ("The Adventure of the Bruce-Partington Plans").


Mycroft Holmes appeared or is mentioned in the following adventures:


Mycroft Holmes has been portrayed by various actors:

Sherlock Holmes Canon
Sherlock HolmesJohn WatsonMycroft HolmesProfessor MoriartyInspector LestradeIrene Adler
Secondary Characters
Mary WatsonMrs HudsonTobias GregsonAthelney JonesSebastian Moran
A Study in ScarletThe Sign of the FourThe Hound of the BaskervillesThe Valley of Fear
Short story collections
The Adventures of Sherlock HolmesThe Memoirs of Sherlock HolmesThe Return of Sherlock Holmes
His Last BowThe Case-Book of Sherlock Holmes
Behind the scenes
Arthur Conan DoyleThe Strand MagazineSidney PagetChronology of Sherlock Holmes Cases