[1] Inspector Lestrade of Scotland Yard brings Holmes a mysterious problem about a man who shatters plaster busts of Napoleon.

Holmes concludes that the burglar wanted to see what he was doing, for there is a streetlamp here, whereas the bust could have been broken at another empty house nearer Harker's, but it had been dark there.

Holmes goes to Gelder & Co. and finds out that the busts were part of a batch of six, but other than that, the manager can think of no reason why they should be special, or why anyone would want to destroy them.

That evening, Lestrade brings news that the dead man has been identified as Pietro Venucci, a Mafioso.

Beppo shows up, enters the house, and comes back out of the window minutes later with a Napoleon bust, which he proceeds to shatter.

Beppo somehow got the pearl from Pietro Venucci, and hid it inside a still-soft plaster bust at the factory where he worked, moments before his arrest for the street-fight stabbing.

After this he is only mentioned by Holmes or Watson – in "The Disappearance of Lady Frances Carfax" and "The Adventure of the Three Garridebs" – as a working member of the Yard.

[3] It was included in the short story collection The Return of Sherlock Holmes,[3] which was published in the US in February 1905 and in the UK in March 1905.

[6] Dressed to Kill – also known as Prelude to Murder (working title) and Sherlock Holmes and the Secret Code (in the United Kingdom) – is a 1946 adaptation loosely based on "The Six Napoleons", the busts being replaced with musical boxes.

[8] This story was dramatised in the popular Granada Television Sherlock Holmes series starring Jeremy Brett.

In the original story, Beppo is captured after killing Venucci and his punishment is left unsaid for the audience to guess.

[9] The opening episode of season 4 of the BBC series Sherlock is called "The Six Thatchers" and is based loosely on this story; at one point Sherlock believes that the suspect is hunting for the black pearl, which he had been asked to look into earlier and dismissed as uninteresting, but it is soon revealed that the suspect is actually hunting for a memory stick containing information about Mary Watson's past.

The glass pearl contained a ring with a hollow compartment that Lucrezia Borgia put poison used to kill her family's enemies.

When she fell out of favour with certain members of the Vatican, she was told to dispose of the ring, her favourite murder weapon.

The episode was adapted by Edith Meiser and aired on 25 May 1931, with Richard Gordon as Sherlock Holmes and Leigh Lovell as Dr.

[13] A radio adaptation of the story was broadcast on BBC Light Programme on 7 December 1954 with John Gielgud as Holmes and Ralph Richardson as Watson.

[14] Michael Hardwick adapted the story for the BBC Light Programme in 1966, as part of the 1952–1969 radio series starring Carleton Hobbs as Holmes and Norman Shelley as Watson.

[15] An adaptation of the story aired on BBC radio in 1978, starring Barry Foster as Holmes and David Buck as Watson.

[18] The story is referenced in The Three Investigators book #7 The Mystery of the Fiery Eye which deals with a hidden gemstone and false clue of busts, used by a Holmes afficianado.