This chapter, by merging a qualitative and quantitative approach, focuses on the evolution of business groups in Italy during the twentieth century. By adopting network analysis, and by using a large and comprehensive dataset, the authors offer various proxy measures of the relevance of the largest business groups in the Italian economy. By also providing a taxonomy, the analysis clearly shows the persistence of large and entangled business groups in the Italian economy. Moreover, it shows that business groups are present not only among large firms, but in almost all the dimensional and juridical forms of Italian firms. The chapter, by challenging the conventional wisdom, confirms that business groups are neither limited to the less develop...