The present volume is a collection of reviews, essays and personal reminiscences on Occhialini's scientific life and work. Through these recollections the reader will also gain a vivid impression of the pioneering days of elementary particle physics when new detection methods emerged, like the triggered cloud chamber and nuclear emulsions - two techniques perfected by Occhialini - which made progress on comic ray physics possible in the first place.

Occhialini Scientific Life.- The Arcetri School of Physics.- Giuseppe Occhialini and the history of cosmic-ray physics in the 1930s: From Florence to Cambridge.- Occhialini’s trajectory in Latin America.- Occhialini’s scientific production between the two English periods.- Occhialini’s contribution to the discovery of the pion. An interview by L. Gariboldi.- Occhialini and the Università Libre de Bruxelles. An interview by L. Gariboldi.- Elementary-particle physics at the University of Milan 1951–1956.- Giuseppe Occhialini in Milan in the sixties and beyond: His legacy for particle physics and his influence on young researchers and students.- Giuseppe Occhialini and CERN.- 1960–1970: Milano and Gruppo Spazio.- La Collaboration Milano-Saclay-Palermo.- Beppo Occhialini and the birth of Space Physics in Italy and in Europe: Personal memories.- An Italian school of high-energy astrophysics: A personal view from the sixties to Beppo-SAX.- Beppo and space research in Italy.- Brief summary of the LFCTR/IFCTR history.- Present Day Perspectives in Research Fields Pioneered by Occhialini.- Are diamonds for ever, or do protons decay? A tale of the unexpected.- Present appeal in pion decay studies and applications.- On the origin of cosmic-ray electrons.- Perspectives of high-energy astrophysics.- Personal Reminiscences.- Personal remembrances.- Working with Beppo: Personal recollections.- G. P. S. Occhialini: One of my masters.- G. P. S. Occhialini vu par un de ses amis.- Early cosmic-ray experiments on ESRO satellites — Some memories of via Celoria.- Beppo Memoire. Space in late’ 60s Milan.- Beppo and the road to INTEGRAL.