This volume of original articles, collected papers and commentaries by contemporary scholars illustrates the work of Tullio Regge, a giant in the panorama of theoretical physics in the second half of the 20th century, probably the most influential Italian physicist after Enrico Fermi. His brilliant contributions to quantum theory and to general relativity have marked significant turning points in the development of scientific knowledge: Regge poles, Regge behaviour, Regge calculus and his geometric approach to general relativity and its extensions, and they continue to have a profound impact on the work of the large theoretical community today. Moreover, his public engagement for the dissemination of scientific culture, his mastering of multimedia technology for outreach and play, and his support for important social causes such as the fight against pseudosciences and the rights of the disabled make him a charismatic character across time, space and disciplines.