Louis-Gaston de Ségur began his career as a diplomat and was attached to the Embassy at Rome when, in 1842, he left his post and entered the Seminary of Saint-Sulpice to prepare himself for the priesthood. He was ordained in 1847, after which he dedicated himself to the evangelization of the people of Paris; the children, the poor, the imprisoned soldiers to whom he was a volunteer chaplain, occupied his ministry until he was appointed to be the auditor of the Rota for France at Rome. While carrying out his judicial functions there, he also conducted some political negations on behalf of Napoleon III, and was honoured with the affection and esteem of Pius IX. However, he lost his sight in 1853, and although he tried to continue to perform his duties, he resigned in 1856 and returned to Paris, where he took an apartment, with Abbé Diringer as his secretary and an ex-solider as his personal servant. He rose each day at five, heard confessions, said Mass, preached, and wrote books. The majority of his time, however, he devoted to religious works, the chief of which were the patronage of young apprentices, workingmen’s societies, and military chaplaincies, and the evangelization of the suburbs of Paris. He also founded the St. Francis de Sales Association for the defence and preservation of the Faith.
Photographed by Disdéri of Paris.