In 1857 the Gunzburgs arrived in Paris from Russia with their large family, a retinue of business staff and extensive domestic help: personal assistants, secretaries, tutors, wet-nurses and nannies, coachmen, ladies' companions, valets and maids, and even a kosher cook. For the Gunzburgs were practising Jews who observed every religious law whilst also launching themselves into Parisian high society. Napoleon III was on a mission to modernise France and the Gunzburgs were quick to avail themselves of opportunities that were opening up - particularly in banking.

The family fortunes prospered through hard work, foresight and marriage. Soon the family was playing a leading role in the Jewish communities of both Russia and France, alongside their contemporaries or relatives the Ephrussis, the Rothschilds, the Brodskys, the Camondos and the Sassoons.