Abstract
After the trial run in Zürich (1897), the International congresses of mathematicians officially began with Paris (1900) and Heidelberg (1904). The third was held in Rome (1908). This order was not random, nor was it dictated only by contingencies. The fact is, at the beginning of the twentieth century Italian mathematics was considered the third world “power”, immediately after the great and traditional French and German schools. The same classification holds, almost completely unchanged, at the beginning of the 1920s. American mathematician G. D. Birkhoff, particularly attentive to the situations of European research centres (and interested in consolidating collaborations with them for the definitive launch of the mathematics of the United States) does not hesitate to place Rome immediately after Paris, even before Göttingen.
But who was in Rome in those years? Who were the mathematicians who made it possible for Italian mathematics to compete with the more famous schools of Europe (and therefore, for the moment, of the world)?