This book aims to provide a comprehensive legal analysis of problems concerning membership, the structure of the United Nations organs, their functions and their acts taking into consideration the text of the Charter, its historical origins, and, particularly, the practice of the organs. One of the aims of the book is to trace precisely the `story' of the United Nations from its birth through an analysis of the practice. Moreover, since the Charter has never undergone any substantive modifications, one cannot exclude that what may appear to be old and obsolete today could become of current interest in the future. This volume is the up-to-date English version of the fifth edition of an Italian textbook on the United Nations which was first published in 1971. An extensive bibliography conveniently precedes every section in each of the chapters, which is of substantial value to anyone studying the United Nations.