221B Baker Street

221B Baker Street is the London address of the fictional detective Sherlock Holmes, created by author Sir Arthur Conan Doyle. In the United Kingdom, postal addresses with a number followed by a letter may indicate a separate address within a larger, often residential building. Baker Street in Holmes' time was a high-class residential district, and Holmes' apartment was probably part of a Georgian terrace.

At the time the Holmes stories were published, addresses in Baker Street did not go as high as 221. Baker Street was later extended, and in 1932 the Abbey National Building Society moved into premises at 219–229 Baker Street. For many years, Abbey National employed a full-time secretary to answer mail addressed to Sherlock Holmes. In 1990, an inauthentic blue plaque signifying 221B Baker Street was installed at the Sherlock Holmes Museum, situated elsewhere on the same block, and there followed a 15-year dispute between Abbey National and the Holmes Museum for the right to receive mail addressed to 221B Baker Street. Since the closure of Abbey House in 2005, ownership of the address by the Holmes Museum has not been challenged, despite its location between 237 and 241 Baker Street.

We met next day as he had arranged, and inspected the rooms at No. 221B, Baker Street, of which he had spoken at our meeting. They consisted of a couple of comfortable bed-rooms and a single large airy sitting-room, cheerfully furnished, and illuminated by two broad windows.
(Arthur Conan Doyle, A Study in Scarlet, 1887)

When the "Sherlock Holmes" stories were first published, street numbers in Baker Street did not go as high as 221.

The section north of Marylebone Road near Regent's Park – now including 221 Baker Street – was known in Conan Doyle's lifetime as Upper Baker Street. In his first manuscript, Conan Doyle put Holmes' house in Upper Baker Street. However, a British crime novelist named Nigel Morland claimed that, late in Conan Doyle's life, he identified the junction of Baker Street and George Street, about 500 metres south of the Marylebone Road, as the location of 221B. Sherlockian experts have also held to alternative theories as to where the original 221B was located and have maintained that it was further down Baker Street.

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