CP violation has become one of the central problems of subatomic-particle physics. Both the LHCb experiment, in operation at the CERN Large Hadron Collider, and the Belle e+e- "B factory," soon to be in operation in Japan following a substantial upgrade, were conceived for its study. A subtle difference between the properties of particles and of antiparticles, CP violation has been postulated (by Russian physicist Andrei Sakharov) to have been responsible for the development, shortly after the Big Bang, of the slight excess of matter over antimatter from which the entire material universe has since evolved. CP violation has been convincingly established in decays of the neutral K and B mesons. More than fifty years of experimental effort in its study have succeeded in determining only two parameters of the theory -- parameters that explain no other known effect. Should CP violation be observed in decays of charmed particles or hyperons, or in neutrino oscillation, there is reason to hope for a breakthrough in its understanding.