Franz Joseph I was the Emperor of Austria and King of Hungary, Bohemia and Croatia. A member of the great Habsburg dynasty, he ascended the throne after his uncle, the Emperor Ferdinand, was forced to abdicate in the revolutions of 1848. A staunch conservative, his lengthy reign was one of the longest in European history. Nevertheless, he largely spent it attempting to resist the fracturing of the Austro-Hungarian Empire in the face of numerous nationalist uprisings; under him, Austria was forced to relinquish much of its territory in Italy, and cede leadership of the German states to Prussia (later the German Empire). His personal life was marred by numerous tragedies, including the suicide of his son and heir, Crown Prince Rudolf, in 1889 and the assassination of his wife in 1898. Defeats in central Europe caused Austria to turn its eye on the Balkans, where an aggressive policy created tensions with Russia and its allies that culminated in the assassination of Franz Joseph's nephew Franz Ferdinand and his wife by a Serbian nationalist in 1914. This murder sparked a conflict that would eventually develop into World War I; however, Franz Joseph died two years into the war.
Sherlock Holmes and Watson celebrate Von Bork's capture by sharing his prized wine, a bottle of Imperial Tokay. Holmes remarks that Von Bork assured him that the wine was from Franz Joseph's personal cellar at the Schönbrunn Palace in Vienna.
The suicide of Franz Joseph's son, Crown Prince Rudolf, is a minor plot point in the film: Holmes implies that his death was actually organized by Professor Moriarty. Later, Franz Joseph's brother, the Archduke Karl Ludwig, represents Austria at the peace summit at the Reichenbach Falls.