Universality of the Weak Interactions, Cabibbo theory and where they led us

Universality of the weak interactions is reviewed, with special emphasis on the origin of the Cabibbo theory of strange-particle ß-decays and its role in the discovery of the unified Electroweak Theory. Achievements and present challenges of the Standard Theory of particles interactions are briefly illustrated. As a homage to Nicola Cabibbo, his leading role in the Roma school of theoretical physics and in the Italian science in general is reviewed. A selection of papers by Cabibbo and other authors, reprinted from Il Nuovo Cimento and historically related to the arguments considered here, is presented. The picture is completed with the classical paper by Cabibbo and Gatto on electron-positron collisions and Cabibbo’s paper on the weak-interaction angle, reprinted from Physical Review and Physical Review Letters, respectively.