The material sources of the scientific enterprise: The libraries of the geometers of the Italian School

The study of the libraries of a social group provides valuable information on the evolution of the social group itself. In other words, the heritage of a School reflects its history by reproducing its chronology, activity and social dynamics. This paper offers the first historical analysis of the libraries of a scholarly mathematical community in Italy - the Italian School of Algebraic Geometry -, basing on a thoroughly exam of the personal book collections of some of its members (C. Segre, G. Fano, F. Enriques, F. Severi and A. Terracini), working between the 80-s and the second world war.