| Kingdom of Italy|
|Head of State||Umberto I (1878-1900)|
|Head of Government||Prime Minister|
|Appearances|| "The Adventure of the Naval Treaty"|
"The Adventure of the Six Napoleons"
"The Adventure of the Red Circle"
"The Adventure of the Three Gables"
The Kingdom of Italy was a country in southern Europe. It was bordered to the northwest by France, to the north by Switzerland and Austria, to the west by the Tyrrhenian Sea, to the east by the Adriatic, and to the south by the Mediterranean.
The country was established in 1861 during the unification of Italy under the kings of Piedmont-Sardinia, though the city of Rome was not conquered until 1870.
In 1889, Italy and the United Kingdom signed a secret treaty clarifying Britain's position towards the Triple Alliance (Italy, Germany, and Austria-Hungary) should France gain complete naval ascendency over Italy in the Mediterranean. This treaty was later stolen from the Foreign Office in London, a crime investigated by Sherlock Holmes.
Giuseppe Gorgiano, Gennaro Lucca, and Emilia Lucca are all Neapolitans from the district of Posillipo in Naples. Gorgiano and Gennaro were members of a dangerous secret society called the Red Circle, an offshoot of the radical Carbonari.
After Mr Douglas Maberley, a British attaché in Rome, died of pneumonia, his belongings and personal effects were sent to his mother, Mary, in Harrow Weald, London. These belongings would form the centre of a series of incidents that Holmes and Watson investigated at the lady's request.