For a long time after the discovery in 1964, by Christenson, Cronin, Fitch and Turlay, that the long-lived neutral kaon decays both into three and into two pions, which has since been taken as proof of CP violation, successive new and more precise experiments confirmed the original evidence and provided results compatible with a phenomenological description confining the CP violation to the mixing between neutral kaons and antikaons. However the Standard Model, with three generations of quarks, linking as it does CP violation to the presence of a single non trivial phase in the Cabibbo-Kobayash.