During the Second French Empire, the reign of Emperor Napoleon III (1852–1870), Paris was the largest city in continental Europe and a leading center of finance, commerce, fashion, and the arts. The population of the city grew dramatically, from about one million to two million persons, partly because the city was greatly enlarged, to its present boundaries, through the annexation of eleven surrounding communes and the subsequent creation of eight new arrondissements.

Avenue Foch is an avenue in the 16th arrondissement of Paris, France, named after World War I Marshal Ferdinand Foch in 1929. Previously it was known as the Avenue du Bois de Boulogne. It is one of the most prestigious streets in Paris, as well as one of the most expensive addresses in the world, home to many grand city palaces, including ones belonging to the Onassis and Rothschild families. The Rothschilds once owned numbers 19–21.