This article relates the long scientific life of the French catholic missionary, Father/Doctor Henri Fontaine. He is also a geologist, a palaeontologist, an expert on Paleozoic corals and an archeologist. The year 2018 marked his 94^th birthday, 70^th sacerdotal year and 64 years of his scientific career. He has devoted most of his life to scientific activities in East and Southeast Asia: from 1954 to late 1975 in Viet Nam as geologist-expert, from 1978 to 2013 in Cambodia, China, Indonesia, Korea, Laos, Malaysia, the Philippines, Singapore, Thailand and Viet Nam, within the framework of the Coordinating Committee for Coastal and Offshore Geoscience Programmes in East and Southeast Asia (CCOP) and afterwards as a volunteer once he had retired. Until 2018, he published nearly 300 articles about geology, palaeontology and prehistory, mostly as sole author or main author. Although he initially intended to be priest living among villagers somewhere in Asia, his life evolved, in spite of himself, following spiritual, political and scientific events.