The Italian Mafia can be seen as one of the largest and most successful businesses in Italy. In one of the latest reports from the Italian Minister of Home Affairs, it has been estimated that revenues from just the informal sector related to the Mafia amount to almost €180 billion. In terms of GDP, revenues from Mafia-related businesses represent almost 12% of the total Italian GDP and are equal to the sum of the GDPs of Estonia, Croatia, Romania, and Slovenia (Ruffolo et al. 2010). To date, the Italian Mafia is the most successful form of organised crime in Europe and comparable to the Chinese, Japanese, Russian, and South American crime organisations in terms of business.In a column at VoxEU.org, Arcangelo Dimico, Alessia Isopi and Ola Olsson look at the Origins of the Sicilian Mafia.