This short and well-written overview provides essential information on the history of international organizations (IOs), with particular focus on the League of Nations, the development of the United Nations, and the UN system. Starting at the beginning of the twentieth century, when there were very few international organizations in existence, A World Beyond Borders traces the growth of IOs through to the close of the century, when there were literally thousands at the heart of the international system. Following this chronological order, the book examines how international organizations became the major legal, moral, and cultural forces that they are today, involved in all aspects of international relations including peacekeeping, disarmament, peace resolution, human rights, diplomacy, and environmentalism. This book is the first in the Canadian Historical Association / University of Toronto Press International Themes and Issues Series, which is dedicated to publishing concise, focused overviews of topics that are of international significance in the study of history.