French protectorate of Tunisia
Dupont was born in Maine et Loire, on 23 July 1850 to a peasant family. After a short and quite successful military service, he died to become a member of the White Fathers missionary society, now called the Society of the Missionaries of Africa. He was ordained a priest on 21 December 1878, and took his oath as a member of the White Fathers the following year. He was then sent to teach at the College of Saint-Louis of Carthage at Thibar in the French protectorate of Tunisia, now in the Béja Governorate. He was later sent to the Karema Mission on Lake Tanganyika in 1892.