アジア・アフリカ会議
After leaving education, Andriamanjato became a Pastor. He also became involved with the nationalist cause. From 1950 to 1957, he studied in France. In 1957, he attended the Bandung Conference and became the leading figure in the section of the nationalist movement opposed to Philibert Tsiranana. He also succeeded the popular nationalist figure Pastor Ravelojaona as pastor of the Ambohitantely Temple in Antananarivo.