Detective fiction: Sherlock Holmes

Sherlock Holmes is one of the most famous characters in fiction. Studying how Arthur Conan Doyle built him, and the detective stories around him, shows how a genre's rules work.

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Doyle and Holmes

Arthur Conan Doyle (1859 to 1930) trained as a doctor in Edinburgh. Holmes first appeared in A Study in Scarlet (1887). The stories are mostly narrated by Dr Watson, Holmes's friend, an army doctor back from Afghanistan. They share rooms at 221B Baker Street, London.
Holmes is famous for deduction: reasoning from small clues to a conclusion.
You have been in Afghanistan, I perceive.
Arthur Conan Doyle, A Study in Scarlet (1887), Part 1, Chapter 1 (Sherlock Holmes, on first meeting Dr Watson)

Conventions of detective fiction

ConventionWhat it means
A crime or mysteryUsually a puzzle the reader can try to solve
A brilliant detectiveOften unusual, with a special method
A companion or narratorWatson asks the questions the reader would ask
Clues and red herringsReal clues, plus false trails to mislead
SuspectsSeveral people who might be guilty
The revealThe detective explains how it was solved

Why Watson narrates

Watson is clever but not as clever as Holmes. Because we see through his eyes, we are amazed with him, and Holmes's thinking stays hidden until the reveal. This builds suspense.
Edgar Allan Poe's 'The Murders in the Rue Morgue' (1841) is often called the first modern detective story; Doyle built on ideas like these.
It is a capital mistake to theorize before you have all the evidence.
Arthur Conan Doyle, A Study in Scarlet (1887), Part 1, Chapter 3 (Sherlock Holmes)
Worked example

Holmes says 'It is a capital mistake to theorize before you have all the evidence.' What does this tell us about his method?

  1. 'Capital' here means very serious.
  2. 'Theorize' means to form an explanation.
  3. So he refuses to decide what happened until he has gathered all the facts.

Answer: Holmes is careful and logical: he gathers all the evidence before deciding on an explanation, rather than guessing.

Key idea

Detective fiction has a mystery, a brilliant detective, a companion, clues and red herrings, suspects and a final reveal. Doyle's Holmes uses deduction, and Watson's narration keeps us guessing.

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Extra practice

2 more questions

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  1. Who is Sherlock Holmes's friend and companion?

    1. Moriarty
    2. Dr Watson
    3. Lestrade
    4. Mrs Hudson
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    Answer: Dr Watson

    Watson narrates most stories.

  2. Who created Sherlock Holmes?

    1. Agatha Christie
    2. Charles Dickens
    3. Arthur Conan Doyle
    4. Mary Shelley
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    Answer: Arthur Conan Doyle

    Conan Doyle wrote the stories.

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Sources and references

Checked by the GCSE-ready editorial team, 17 October 2026. Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.

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