This book is the result of the joint work of the most famous celtologists, Miles Dillon and Nora Chadwick. This is a generalizing and, in some way, summing up the work, containing all the most important data and information collected by Celticology by the mid-60s of the 20th century. Along with the widest coverage of material, the great advantage of this book is the truly scientific approach of the authors, who base their presentation only on reliable and verified information, scrupulous and thorough analysis and comparison of sources. They trace step by step the political and spiritual history of the Celts, examining in detail both the internal development of the Celtic countries and their relationships with the outside world, especially focusing on the impact they had on Western European history and culture. Nevertheless, perhaps it is the chapters devoted to the formation and history of the Celtic states that will seem most interesting to the domestic reader, since this aspect of Celticology has not yet been covered in such a volume and at such a level.