This thesis is an examination of Nguyen Ai Quoc's (Ho Chi Minh's) role in transmitting communism to Vietnam in the period between the First and Second World Wars. As the Third International (Comintern) provided the theory and much of the organizational support for this task, it is also a study of the Comintern's changing policies towards revolution in colonial countries. It has grown out of research in the Moscow archives of the Comintern, which first became available to researchers in late 1991-1992. It also makes extensive use of the French colonial archives at the Centre d'Archives d'Outre-Mer in Aix-en-Provence. This study begins with Nguyen Ai Quoc's appearance in Paris in 1919, when he lobbied the Paris Peace Conference for greater Vietnamese freedom and was then drawn into the political world of the French left. It follows his first contacts with the Comintern in Moscow (1923- 1924), through his two-year sojourn in Canton during the Communist-Guomindang United Front, when he established the first training courses for Vietnamese revolutionaries. Chapters IV and V cover his return to Asia in mid-1928, his founding of the Vietnamese Communist Party in 1930, and the 1930-31 insurrectionary movement in Vietnam. Chapter Six deals with his Jime 1931 arrest and his long period of political inactivity in Moscow, from mid-1934 until the autumn of 1938. The final chapter covers his return to southern China and his efforts to regain his influence in the Vietnamese communist movement from 1939 to 1941. The thesis concludes that, with the benefit of the documentary evidence now available, it is necessary to readjust the perception of Nguyen Ai Quoc as an influential communist during his early political career. Initially he received little financial support from Moscow and he never became a member of the Comintern Executive Committee. Nor did he exist entirely within the world of the Comintern. Although the latter was an essential force in the creation of Vietnamese communism, there were other factors which shaped its growth, including family and regional ties, as well as Chinese and French left-wing politics.