The school brings together leading experimental and theoretical scientists, including many Nobel Prize winners in high-energy physics, outstanding contributors to other fields of physics such as high Tc superconductivity, particle accelerators and detector instrumentation, and talented young physicists selected from candidates around the world. The key experimental discoveries and theoretical breakthroughs of the last 50 years, in particle physics and related fields, have led us to a powerful description of matter in terms of three quark and three lepton families and four fundamental e+e- interactions. The most recent generation of experiments at and proton-proton colliders, and corresponding advances in theoretical calculations, have given us remarkably precise determinations of the basic parameters of the electroweak and strong interactions. These developments, while showing the striking internal consistency of the Standard Model, have also sharpened our view of the many unanswered questions which remain for the next generation: the origin and pattern of particle masses and families, the unification of the interactions including gravity, and the relation between the