The Comparative and International Education Society (CIES) has, throughout its 50 years of existence, exercised leadership in the field of comparative education. It was one of the five societies that founded the World Council of Comparative Education Societies (WCCES) in 1970, an umbrella body that by 2006 brought together 35 national, sub-national, regional and language-based societies. The CIES has continued to play a major role in WCCES affairs. The relationship has had ambiguities, while it has also provided many synergies for the promotion of the field of comparative education on a global basis. This article reviews the relationship between the CIES and the WCCES throughout their intertwined histories. (Contains 3 tables and 5 notes.)