Globalizing Physics: One Hundred Years of the International Union of Pure and Applied Physics.

The talk presents major results of the project "One Hundred Years of IUPAP: A History" with a focus on role of Italian physicists and institutions in various phases the Union's history. It will show that after the IUPAP had been rather inactive in the interwar period, the post-WWII period saw the emergence of various committees devoted to specific sectors of physics. After discussing the major features of this transformation, the talk chronicles main developments of the IUPAP in the following decades and discusses how the scientific activities of the IUPAP were deeply conditioned by the changing political contexts.