Jack Granatstein introduces Reid and the forces that shaped his progressive idealism in the 1920s and 1930s. Hector Mackenzie assesses Reid's contribution to the creation of the United Nations in the mid-1940s, while David Haglund and Stephane Roussel examine Reid's crucial role in the negotiations to establish the North Atlantic Treaty Organization. Greg Donaghy, Bruce Muirhead, and Alyson King write, respectively, about Reid as high commissioner to India, as an important influence on World Bank policy in the early 1960s, and, finally, as founding principal of York University's Glendon College.About the Author: Greg Donaghy (1961-2020) was head, Historical Section, Department of Foreign Affairs and International Trade, and general editor of its series Documents on Canadian External Relations.