UNDER THE SPELL OF THE GAUGE PRINCIPLE - by G 't HooftThe University of Bologna and its Academy of Sciences, in collaboration with the Italian National Institute for Nuclear Physics and the Italian Physical Society, celebrated in 1998 the bicentenary of a great pioneer in the field of electric phenomena - Luigi Galvani, the father of macroelectricity. During these two centuries, the physics of electric phenomena has given rise first to the Maxwell equations, then to quantum electrodynamics, and finally to the synthesis of all reproducible phenomena, the "Standard Model". A cornerstone of the Standard Model is quantum chromodynamics (QCD), which describes the interaction between quarks and gluons in the innermost part of the structure of matter.The discovery of QCD will be recalled in the future as one of the greatest achievements of mankind. Many physicists, the world over, have contributed to its creation on both the experimental and the theoretical front. Professor Antonino Zichichi has played an important role in this scientific venture, as documented by his works which are reproduced in this invaluable volume.One of the founders of European physics, Professor Victor F Weisskopf, contributes with his memories of the time when QCD had many problems. This volume owes its existence to a founding father of QCD, Professor Vladimir N Gribov, whose sudden demise prevented him from directly contributing to its final edition. Two world leaders in subnuclear theoretical physics, Professors Gerardus 't Hooft and Gabriele Veneziano, illustrate the significance of the contributions of Antonino Zichichi in QCD.